Hello, I upgraded my Chromecast a couple weeks ago and I have had no issues with it up until now. I have been streaming youtube videos up until today without issue. Nothing has changed with my app, phone, smart TV, chromecast, or anything else I can think of. This happens with all youtube videos I try to play regardless of whether or not I'm using the app or the Chromcast interface, which makes me think it's a youtube specific issue. I tried with Netflix and their videos appeared full screen, no problem.
I have tried restarting the Chromecast, with no success.
Has anyone run into this issue? Hopefully just a glitch/bug?
Thanks for reaching out. Please try to clear the cache and data of the YouTube app and reboot your Chromecast. Plugging in the Chromecast into a different HDMI port on your TV and resetting your Chromecast might also help.
Also, if the issue is isolated when using the YouTube app, please reach out to YouTube support for further help.