My vimeo is working on web and Mobile app. Just tested with a normal public vimeo video.
I'm on Moodle 3.5:
- Allow Frame Embedding is not enabled. My understanding is that this setting is if you want your Moodle site to be embedded into other systems e.g. when using LTI.
- I just went to Site Administration > Plugins overview > Multi media plugins (must be enabled > click on settings > click on Manage Media Players. then in-line with Vimeo, just enable it. See attached. It then immediately worked.