diff --git a/frontend/src/components/admin/PermissionMatrixTab.tsx b/frontend/src/components/admin/PermissionMatrixTab.tsx
index b189711..9018c48 100644
--- a/frontend/src/components/admin/PermissionMatrixTab.tsx
+++ b/frontend/src/components/admin/PermissionMatrixTab.tsx
@@ -460,67 +460,57 @@ function PermissionMatrixTab() {
                         })}
                       </TableRow>
 
-                      <TableRow>
-                        <TableCell colSpan={2 + nonAdminGroups.length} sx={{ p: 0 }}>
-                          <Collapse in={isExpanded} timeout="auto" unmountOnExit>
-                            <Table size="small">
-                              <TableBody>
-                                {(() => {
-                                  let lastSubGroup: string | null | undefined = undefined;
-                                  return fgPerms.map((perm: Permission) => {
-                                    const depTooltip = getDepTooltip(perm.id);
-                                    const tooltipText = [perm.description, depTooltip].filter(Boolean).join('\n');
-                                    const subGroup = getSubGroupLabel(fg.id, perm.id);
-                                    const showSubGroupHeader = subGroup !== lastSubGroup && subGroup !== null;
-                                    lastSubGroup = subGroup;
-                                    return (
-                                      <React.Fragment key={perm.id}>
-                                        {showSubGroupHeader && (
-                                          <TableRow>
-                                            <TableCell
-                                              colSpan={2 + nonAdminGroups.length}
-                                              sx={{ pl: 5, py: 0.5, bgcolor: 'action.selected', position: 'sticky', left: 0, zIndex: 1 }}
-                                            >
-                                              <Typography variant="caption" sx={{ fontWeight: 600, textTransform: 'uppercase', letterSpacing: 0.5, color: 'text.secondary' }}>
-                                                {subGroup}
-                                              </Typography>
-                                            </TableCell>
-                                          </TableRow>
-                                        )}
-                                        <TableRow hover>
-                                      <TableCell sx={{ pl: 6, minWidth: 250, position: 'sticky', left: 0, zIndex: 1, bgcolor: 'background.paper' }}>
-                                        <Tooltip title={tooltipText || ''} placement="right"><span>{perm.label}</span></Tooltip>
-                                      </TableCell>
-                                      <TableCell align="center" sx={{ minWidth: 120 }}>
-                                        <Checkbox checked disabled sx={{ opacity: 0.3 }} />
-                                      </TableCell>
-                                      {nonAdminGroups.map(g => {
-                                        const isGranted = (grants[g] || []).includes(perm.id);
-                                        const curReverseDeps = reverseDeps[perm.id] || [];
-                                        const isRequiredByOther = isGranted && curReverseDeps.some(d => (grants[g] || []).includes(d));
-                                        return (
-                                          <TableCell key={g} align="center" sx={{ minWidth: 120 }}>
-                                            <Tooltip title={isRequiredByOther ? 'Wird von anderen Berechtigungen benötigt' : ''} placement="top">
-                                              <span>
-                                                <Checkbox checked={isGranted}
-                                                  onChange={() => handlePermissionToggle(g, perm.id, grants, groups)}
-                                                  disabled={permissionMutation.isPending} size="small"
-                                                  sx={isRequiredByOther ? { color: 'warning.main', '&.Mui-checked': { color: 'warning.main' } } : undefined} />
-                                              </span>
-                                            </Tooltip>
-                                          </TableCell>
-                                        );
-                                      })}
-                                    </TableRow>
-                                      </React.Fragment>
-                                    );
-                                  });
-                                })()}
-                              </TableBody>
-                            </Table>
-                          </Collapse>
-                        </TableCell>
-                      </TableRow>
+                      {isExpanded && (() => {
+                        let lastSubGroup: string | null | undefined = undefined;
+                        return fgPerms.map((perm: Permission) => {
+                          const depTooltip = getDepTooltip(perm.id);
+                          const tooltipText = [perm.description, depTooltip].filter(Boolean).join('\n');
+                          const subGroup = getSubGroupLabel(fg.id, perm.id);
+                          const showSubGroupHeader = subGroup !== lastSubGroup && subGroup !== null;
+                          lastSubGroup = subGroup;
+                          return (
+                            <React.Fragment key={perm.id}>
+                              {showSubGroupHeader && (
+                                <TableRow>
+                                  <TableCell
+                                    colSpan={2 + nonAdminGroups.length}
+                                    sx={{ pl: 5, py: 0.5, bgcolor: 'action.selected' }}
+                                  >
+                                    <Typography variant="caption" sx={{ fontWeight: 600, textTransform: 'uppercase', letterSpacing: 0.5, color: 'text.secondary' }}>
+                                      {subGroup}
+                                    </Typography>
+                                  </TableCell>
+                                </TableRow>
+                              )}
+                              <TableRow hover>
+                                <TableCell sx={{ pl: 6, bgcolor: 'background.paper' }}>
+                                  <Tooltip title={tooltipText || ''} placement="right"><span>{perm.label}</span></Tooltip>
+                                </TableCell>
+                                <TableCell align="center">
+                                  <Checkbox checked disabled sx={{ opacity: 0.3 }} />
+                                </TableCell>
+                                {nonAdminGroups.map(g => {
+                                  const isGranted = (grants[g] || []).includes(perm.id);
+                                  const curReverseDeps = reverseDeps[perm.id] || [];
+                                  const isRequiredByOther = isGranted && curReverseDeps.some(d => (grants[g] || []).includes(d));
+                                  return (
+                                    <TableCell key={g} align="center">
+                                      <Tooltip title={isRequiredByOther ? 'Wird von anderen Berechtigungen benötigt' : ''} placement="top">
+                                        <span>
+                                          <Checkbox checked={isGranted}
+                                            onChange={() => handlePermissionToggle(g, perm.id, grants, groups)}
+                                            disabled={permissionMutation.isPending} size="small"
+                                            sx={isRequiredByOther ? { color: 'warning.main', '&.Mui-checked': { color: 'warning.main' } } : undefined} />
+                                        </span>
+                                      </Tooltip>
+                                    </TableCell>
+                                  );
+                                })}
+                              </TableRow>
+                            </React.Fragment>
+                          );
+                        });
+                      })()}
                     </React.Fragment>
                   );
                 })}