You can stream all the games live several different ways.
At the NCAA website you can live stream any of the 4 games current playing…
2023 March Madness: Men’s NCAA tournament schedule, scores, how to watch | NCAA.com
I like to record digital copies so I go to the actual channels live stream and do a screen record:
CBS → CBS Live TV Stream
TBS → Watch Live | TBS.com
TNT → Watch Live | TNTdrama.com
TRU → https://www.trutv.com/watchtrutv
I hope that give you a few options to view the game
NOTE: These streams seem to work best with my EDGE browser, it doesn’t seem to like Chrome, or Opera. There is a chance that it’s just a setting I have on each browser because I have them set up to do different things. But its also possible that EDGE being Microsoft main go to browser that they put something in it to make it easier to view certain things. I’d not put something like that past Microsoft.