1.11.5 - Inconsistent transparency on thumbnails of various files

[woot000]

Recently updated to XnView MP 1.11.5 on Windows 11 24H2, and I've noticed some thumbnails don't have transparency depending on what type of image they are.

For tab thumbnails, PNGs with palettes (256 colors or less) render transparency as white, but PNGs with 8/16 bits per color (more than 256 colors), WEBPs and JXLs correctly render transparency.

tab thumbnail transparency.png

It's the opposite for viewer thumbnails. Paletted PNGs render transparency with the checkerboard, but PNGs with 8/16 bits per color, WEBPs and JXLs incorrectly render transparency as black.

viewer thumbnail transparency.png

The catalog is enabled, but I do not have thumbnail caching enabled.

catalog and thumbnail settings.png

I have attached the images I used above in a ZIP file for reference.

[xnview]

do you have rebuilt thumbnails, it works here

Capture-1.jpg

[woot000]

Doubled checked and it looks like enabling "Use alpha channel" fixes there not being visible alpha for any transparent image but paletted PNGs, but it looks the same as last time for me with the tab thumbnails. It looks like "Use alpha channel" doesn't seem to apply to paletted PNGs

{8E5506B8-7029-49A6-B91B-DA6BABF738CA}.png

{1658EBB2-1557-4245-9BC6-B5152736DC65}.png

{EF2825FC-A97B-45C3-B514-93E5A2CF1F7E}.png