It seems like the contributions dropdown icons are missing. I checked both enwiki and thwiki and both of them are missing the same icons. I don't know if any other wikis have the same problem due to me not knowing any other wikis that have this feature enabled.
Thanks for the ping.
The above fix will address the situation, provided the language team is happy to own the technical debt associated and handle any future regressions relating to updates in Vector.
Legacy Vector doesn't officially support icons in menus (or callouts) which means this may break in the future, but perhaps given eventually this experience will be restricted to a smaller audience when Desktop Improvements is complete, that will only be a temporary need.