@gifsbot still not really sure what happened but i've switched it to 2x scaling the images instead of 4x in case it was choking on the size, hopefully that helps
(the 4x scaling was done to try and preserve quality on bluesky which has a particularly shitty way of handling images but wasn't necessary for mastodon nor twitter, so i've now made it only scale to 4x for bluesky specifically and reverted to 2x for the others)
@gifsbot there does seem to be a known issue with mastodon which can cause what i saw. but honestly it could equally be a bug in my code. who knows. not me because i'm not logging anything https://github.com/mastodon/mastodon/issues/21864