if someone has the video size problem in full-screen mode in Chrome Android context;

the problem may come from default page zoom ; parameters / content parameter / Accessibility / default page zoom. set it back to 100% (or around 91%) and it should be good.

and a faster way, not modifying parameters, is to show the web page in 'version for computer' (parameter three dots) and from there, put the video in full-screen mode.

friendly