Looks like it might have done - I don't seem to be able to reproduce the issue anymore

I'm no longer getting the stream of errors I was earlier after enabling the Navigation Popups gadget, so it (crosses fingers) seems to be fixed for me :)

I think this should be filed under Navigation-Popups-Gadget - the errors occur for me when this gadget is enabled.

Apologies if this info is unnecessary/unhelpful, but I just received a 500 error attempting to load a thumbnail for this image, and thought I should copy it here in case it would be aid investigations (given the comment about the throttling masking the real error source).

@hnowlan I believe it did - I briefly saw a thumbnail myself at one point, and onwiki it was reported that "there were no issues when [the photo was put] in the original template" (ie. before it moved to the main page). Regarding the HTTP error code, at one point since filing this report I remember seeing a 500 (with the same Wikimedia error screen); however I'm afraid I didn't copy the full message. If it would be helpful, I can add the details here if I see a 500 again.

Should T205224 be reopened? By my understanding, that task was related to the Thanks extension itself, and this one was for enabling the ability on Wikimedia wikis. I might be missing something here, though.

Admittedly I’m inexperienced here (and so may well be missing something), but in T354858, I received 429 errors that do actually seem to be as a result of a technical problem (rather than the same client repeatedly making requests).

Adding SRE as from what I've read it seems like it might be a relevant team here. Apologies if this is incorrect.

A VisualEditor bug on enwiki (which, according to Special:Version, is currently running MW 1.42.0-wmf.12) that seems similar to this one was reported on the Wikimedia Community Discord today - "Revision IDs returned by the server do not match (document: 1194632572, metadata: 1194632654)" . I just wanted to drop a comment in here in case it's the same bug, and it turns out it hasn't been completely fixed. (I'm commenting rather than opening a new task as I don't personally have the information necessary to do so - but I thought that this bug report on Discord was worth noting, given that this was recently closed).

Noting for the sake of this bug report that what jpxg describes has also been happening to me (Safari on iOS). The only thing I’ve noticed that sometimes fixes it is repeatedly refreshing the page - which sometimes results in the section expanding correctly after one of the refreshes.

I’ve been having a very similar issue, but worth noting that for me, a refresh hasn’t always been fixing it on the first try. I’m using Safari on iPhone.