I would first point out that Vimeo is not “relaying” anything to CHoP, because CHoP is nothing more than a website that embeds the player of your video provider… in this case, presumably the Vimeo player is what you’re using on CHoP because you’re using Vimeo for streaming. However, they are (likely) sending a stream on to Facebook on your behalf (a common thing for streaming services to do).
All that said, if you’re seeing issues on BOTH Chop (Vimeo player) and Facebook, this either implies the entire streaming service (Vimeo) is having trouble, OR that your stream is not getting to them reliably. If Facebook is perfect and the Vimeo player is not, this implies the problem is somewhere else as you couldn’t get perfect video relayed to FB if your stream wasn’t getting out perfect, either.
I’ve seen a lot of chatter about churches wanting to switch to Vimeo (live) for the low price point, but we chose to go with Living As One for our live streams to gain the resiliency that platform provides. As is often (but not always) the case, you get what you pay for.