been running it in docker for over a year now with the docker hub image. I'm assuming you got to the app site page based off of what you described. I'd imagine it may be something related to the video quality/encoding option? Does the metadata come through when you search for a video? Also, I find Invidious tends to be (rightly so) particular with the TLS stapling option, so if you don't have tls or a proxy in front of it, then make sure it's set to off (happened to me with self signed certs and nothing would play)

Without more info it'll be hard to help.

I got it working in principle, but the Raspberry Pi I wanted to host it on isn't powerful enough to handle the necessary computing.

I've been using ViewTube specifically because it was easier to set up. Although it also fails to play videos occasionally

I've been running it in Docker for a few months without serious issue. The only problem I've seen is website with embedded YT videos and it not liking mixed HTTPS (site) and HTTP (my instance) on the same page, but that's a CSP issue that can be worked around, depending on your browser or whether you run HTTPS on your network.

I'm using the quay.io/invidious/invidious:latest and docker.io/library/postgres:14 images and a docker-compose based on this one. The main difference I made was to use a real database directory rather than using a dynamic volume. But other than that, it's pretty unchanged.

I also followed https://docs.invidious.io/redirector/ (rules 1-8) to redirect YT URLs to my instance.

I installed it behind traefik (proxy) via d.rymcg.tech and it's been working fine.

Why are you building the image yourself? Not that there's a problem with that necessarily, but it seems a bit wasteful of your resources unless you have a specific reason to do so. There's a docker image (quay.io/invidious/invidious:latest) built by the developers that gets updated pretty frequently. I've been using it for years now and it's been working perfectly fine for me the whole time.