Partially chosen with the hope that they’d work well together. My TV is an Android TV, made for Google integration with a built-in YouTube app, and my phone is a Pixel phone.
The issue is widespread, and pre-dates YouTube’s limitations put in place during the pandemic. If I change the resolution to 1080p, YouTube stubbornly continues to play the video in a resolution that belongs in the 90s. Every time I do, the video shows in 480p, even though I have a fiber connection on which YouTube never buffers.
To watch YouTube videos from my phone, which is where I find them, on my TV, which is where I want to watch them, I’ve long since thrown up my hands and given up using the Cast function of the app.