Certain stickers do not appear in sticker list

Guidelines

• I have searched open and closed issues for duplicates
• I am submitting a bug report for existing functionality that does not work as intended
• This isn't a feature request or a discussion topic

Bug description

I've noticed this issue for a while now where there is a clear disparity between the stickers available in a pack when viewed through Signal Desktop (which appears to show all stickers within a pack) versus Signal Android (which appears to show a fixed subset).

For example, when using this specific Signal sticker pack, the stickers are shown in the desktop app as follows:

However, on mobile, several of these stickers are missing. They are not simply broken or showing no preview like I've seen reported in other issues, but they are straight up missing, as in the twelve shown above are not the same as the twelve shown on mobile.

The stickers sent from desktop can be tapped and shown to reveal the sticker pack on mobile, though you do not see that sticker in the preview list. The sticker can also be forwarded on mobile and function as a sticker, but again, it can't be viewed or sent directly from the sticker collection.

I don't know how to tell for sure, but it seems like these stickers are homogeneous in their file type, so there shouldn't be anything wonky with a disallowed file extension. It just seems almost idiosyncratically that some stickers are removed from view.

This pack is also not the only pack in which this bug appears.

I assumed there might have been an issue with certain emojis used that are available on desktop but not on Android, but that doesn't appear to be the case (such as the above first sticker using a crossed swords emoji that is available on both).

I also assumed there might be a soft limit on packs with a lot of stickers, but even if this is a case it doesn't seem to apply (this pack has a lot more stickers available on mobile compared to another pack that has this issue but shows less).

Screenshots

Shown above.

Device

Likely not relevant. Not going to provide.

Android version

Android 16

Signal version

8.19.2

Link to debug log

May provide if necessary though in redacted form.

No source file or test is named in the report. Start by reproducing the missing-sticker behavior on Android 16 with the linked pack, comparing its mobile and Desktop sticker lists; done means identifying why valid stickers are omitted and confirming that the affected stickers appear in the collection.