I'm writing up a solution to my problem. Who knows may help someone.
- Home wireless router WiFi 5Ghz band enabled
- Laptops can connect to 5Ghz no problem
- no gPixels could even see the the 5Ghz network.
- Was it GrapheneOs, the Router, the handset hardware?
Solution:
- router had an 5Ghz WiFi option: 802.11ax / WiFi 6 mode: enabled.
- Many, all(?) bar some v9 pixels can't handle it.
- As soon as it was disabled, the 5Ghz WiFi became available.