Have a Sony Bravia KD-55X7500H (55" 4K w/ Android TV OS 11).
I've sideloaded the latest Firefox, Brave, and TV Bro. Each one of them displays what appears to be just the upper left 1/4 of the entire screen I should be seeing.
I've tried switching to the Desktop version of sites (same result).
There doesn't appear to be any setting or command to zoom in/out (I have a keyboard also, and no key combo seems to work, e.g. CTRL plus +, I, up-arrow, etc.).
Any thoughts - I've seen a few other people referencing the same issue, but no solutions.
I don't have that TV but have seen this behavior before in an Android TV IPTV device. The solution ended up being that I went into Settings and Accessibility and finding that the "Screen Magnifier" was turned on. After turning it off browsers and apps acted normal again. Could that be your problem?