Responsiveness back to normal soon after the update. However, this seems to be persist intermittently:
Often, when it happens, it is longer than 30s. The upload counter can also be stuck at 100% with an inactive Reply button.
Creates a lot of user anxiety, at least for me. I have to cancel or log out, and keep an offline copy of the post in case it doesn't get saved.
I haven't tested it objectively but maybe it has to do with uploading multiple files; partially uploading something then removing it to upload something else; or uploading it and typing at the same time. E.g., this is repeatable: removing the space after
[Uploading...]() disrupts the upload.