Sorry I already opened a similar topic a few days ago but it is closed now because I thought the problem came from somewhere else.
It appears that after vimeo changed their thumbnail urls, every vimeo embed in my site has broken thumbnail (the default one is then showed which has vertical colored bands). In fact the only way I found to resolve this problem is to delete the videos and add them back again (see video below).
I thought the problem came from my application but in fact it doesn't, because if I check with my repo browser api, I don't get the right thumbnail either. After deleting the video and setting it back, the api returns the right thumbnail url.
Here is the video mentioned above :
And here is what the browser api gives me before changing anything :
And after deleting the video and setting it back :
So to sum things up my question is, is that something you can fix? If not, I will try to bulk re-import all my documents