I have Samsung UE40J5200AW and it has that screen mirroring feature. Whenever I try to use to cast from Windows 11 to this TV, the stream stops after few mins of playing.
I have no idea if Samsung doesnt allow to play full screen videos from casting devices or not. I have tried to connect both PC and TV via Ethernet and see if it will help, but its happening all the time.
Whats interesting it also happens when I cast via my lineage os phone and I checked it on different TV and had the same issue.
Whats your ways to cast videos from PC/laptop to TV?
I use a Steam Link, but that's no longer available as hardware, only an app. I don't have any experience with it but I read somewhere you can set up RaspberyPi to work in the same way.
Though I have to say - while it works wirelessly, for games it is better to have wired connection.
https://www.samsung.com/ie/support/tv-audio-video/how-to-screen-mirror-laptop-to-tv/
Try a file app that allows you to view local network devices. If not, with a little more configuration you can find out about Kodi or Plex
I've used Moonlight (app) and Steam Link (both the app and discontinued physical hardware). They're both pretty decent, but I haven't used either in ages.
It depends on what you're trying to run, but both are free so you should just give it a try.
Edit: I misread the original post as being some silly question. I used to use the physical Steam Link for watching videos a long time ago, but if you're just running video files I'd recommend something like Plex.