Cookies are allowed and I don't use AdBlock, but uBlock Origin. translatewiki.net wasn't whitelisted in my extension, but doing so doesn't help.
Sorry, I did indeed saw the recording, but couldn't make it bigger and I don't see well.
I remember a similar problem happening on Beta Cluster wikis, but I don't know how they finally solved it; and cannot find a task either.
TWN-staff: are you aware of more users experiencing this issue?