Created attachment 184823 [details]
Tests & Conclusions & Ruled out Possibilities

SUMMARY:

Dolphin - Intermittant Displaying Previews of 'Folder' Thumbnails on NTFS Drives/Partitions


STEPS TO REPRODUCE

1. Using Dolphin, have Previews on, and goto an NTFS Drive/Partition with videos on it (root or folder)


OBSERVED RESULT:

Observe any/all 'Folders' to see the thumbnails being generated on them
Note that many folders will never show any thumbnails despite the folder having videos in it

Please note, Im not talking about the actual video file thumbnails themselves, they display fine 100% guaranteed all the time perfectly
Im referring to the actual 'Folder' icon itself, that normally would display 4 separate thumbnails on the folder icon itself if the folder has at least 4 video files in it

I have folders with mixed video file types


EXPECTED RESULT:

All folders that have at least 1 video in them should display at least 1 video thumbnail on the folder


SOFTWARE/OS VERSIONS:

Operating System: openSUSE Tumbleweed 20250904
KDE Plasma Version: 6.4.4
KDE Frameworks Version: 6.17.0
Qt Version: 6.9.2
Kernel Version: 6.16.3-1-default (64-bit)
Graphics Platform: Wayland
Processors: 12 × 11th Gen Intel® Core™ i5-11500 @ 2.70GHz
Memory: 32 GiB of RAM (31.2 GiB usable)
Graphics Processor: AMD Radeon RX 6600
Manufacturer: Gigabyte Technology Co., Ltd.
Product Name: H510M DS2V



ADDITIONAL INFORMATION:

File Krusader v2.9.0 "Sixth Life" - RPM Installation
Also has this problem:

https://bugs.kde.org/show_bug.cgi?id=509015


POSSIBLY RELATED BUGS:

File preview on some locally-mounted drives (NTFS, NFS, SMB) inappropriately use remote preview settings
https://bugs.kde.org/show_bug.cgi?id=451408



I have included an attachment text file which is a list of various tests and things i have been able to rule out
as related to this