I was also having WIFI issues. My RPI4 is running LE 9.2.3 and I have the country code properly set. However, I still don't see the 5Ghz band and I suspect my FLIRC case is interfering so I am getting some pretty low throughput on 2.4.
I decided to go the bridge route and now I am getting great speeds. If anyone is interested, I bought this unit and so far I'm quite happy:
Cheers.