Macbook not connecting to 5GHz wi-fi/Chromecast

Most weeks I run a D&D game at a friend’s house. They have a small TV set up with a Chromecast (1st gen). We’ve had some issues with my Macbook Pro (13-inch, 2017, Two Thunderbolt 3 ports) only connecting to the 2.4GHz bandwidth range of the wi-fi router, and therefore having issues with the Chromecast. One person will cast to it, and then suddenly I won’t be able to cast to it at all. This doesn’t happen all the time, though. Sometimes I can cast to it and override someone else’s cast, but once I can’t cast, then that’s it, only restarting the Chromecast will enable me to recast to it.

Apparently my Macbook isn’t kicking up to the 5GHz range which leaves it locked out when someone else does connect in that range. The Chromecast seems to be prioritising the cast from the 5GHz connection and blocking anything from 2.4GHz. So is there any way to force my Macbook to reconnect to the higher bandwidth?

Easiest solution would be to rename the 5Ghz network if that’s an option. Most routers would let you.