For some reason Vimeo links (embeds) have stopped to be supported even though they are listed as approved. I had to paste a plain URL and I must add that I had had no problem with Vimeo links prior to the latest XenForo update.
I checked your post history and see this Vimeo URL:
https://vimeo.com/626472445/016ba4ae7b
I'm not that familiar with Vimeo, rarely even seen videos from it, but I checked their video listings and the videos listed there all seem to be formatted like this, without the extra bit at the end:
https://vimeo.com/605584471
I tried that video link and it embedded fine.
I tried trimming your video link down like that, but it just shows "video not found". I'm guessing that bit at the end is a key, and access to this particular video is restricted to those who have that key on the end?
If that's the case, I can at least report it to the XenForo devs to fix their Vimeo embed code to support those restricted access (or whatever they're called) video URLs.