Sinc eit works for you for Lemmy, Iit is likely that you know how to use that feature 😀 That's enough to check for differences between the different actors.

Can you take a screenshot of the message header (means the top of the message including the date and time, but without the post itself) of one of these Peertube videos where you hadn't been notified? I would like to check some values there to be sure.