Created attachment 168788 [details]
Remote vs Local view.

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SUMMARY


STEPS TO REPRODUCE
1. Open Dolphin
2. Open Configure Dolphin > Interface > Previews, making sure "Folders" is selected
3. Set "skip previews for remote files above" to "999999 MiB" and Apply
4. Make sure View (menu) > Show Previews is enabled
5. Use Dolphin to browse to local ~/Pictures/ and observe directory thumbnails (of pictures/videos within those directories) are being shown
6. Use sshfs to mount a SFTP directory with pictures (e.g. `sshfs user@192.168.1.234:~/Pictures ~/sshfsmount`)
7. Use dolphin to browse to the mounted sshfs directory. Observe no directory thumbnail is being shown. Note that individual files' thumbnails are still shown correctly.
8. Use dolphin to view the same remote directory (by typing in `sftp://user@192.168.1.234:~/Pictures` in the address bar). Observe the network mount via dolphin/kio also had individual file thumbnails but did not have directory thumbnails.
9. Use Nautilus to mount the same network folder, via GVFS. This mounts the remote directory at /run/user/1000/gvfs/sftp:host=192.168.1.234,user=user. Use Dolphin to browse to this location. Observe that this also results in only individual files having thumnails but no directory/folder thumbnail.

OBSERVED RESULT
Folder thumbnails only work on local directories.

EXPECTED RESULT
Folder thumbnails should also work on remotely mounted directories.

Note that all files in the example directory used are under 5MB, and the entire directory is under 200MB.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: 
(available in About System)
KDE Plasma Version: 6.0.4
KDE Frameworks Version: 6.1.0 
Qt Version: 6.7.0
Kenrel 6.8.7 on Wayland

ADDITIONAL INFORMATION