Here's my story with this issue.
Recently, I've bought a MacBook Pro 16" M2 Pro.
First, at the setup I noticed I was unable to connect to 5GHz Network!
So, I connected to 2.4GHz Network, which worked perfectly.
After the setup was completed, I was trying to connect to the 5GHz Network!
I couldn't connect to 5GHz at all, so I reached out to Apple Support, they told me I should do a complete MacOS reset. After the full MacOS reset, I was struggling with the same issue. I was going to give up, and return my new Mac device. Lastly, I reached out to my ISP, and they told me I should try on a different router. So, I bought a TP-LINK Archer C6 Router. I successfully connected to the 5GHz network. For all the Apple users, who struggles with the same issue. My suggestion is: Try out the 5GHz connection with a different router. My problem solved. :)