Oh, I see, sorry, I was a bit confused by your previous post. I made the change, rebooted, and all is good.
I thought that my other RPi4's where on the 5ghz network, but I guess they were not. Perhaps I didn't really care, because the 2.4 was working and all was good. But this particular installation, not all is good and that was why I started looking for the 5ghz.
Thanks, this solved my issues.
In 9.2.1 onwards, in the network settings (in the LE settings add-on).
I don't see anything in the network Settings. But then you add (in the LE settings add-on). Is there an additional add-on that has this setting?