A1222+ and Radeon RX550 - works in boot menu but not AmigaOs 4.1

[OldAmigan]

@kubatyszko

I only have Display Ports on my Radeon R550 card in my A1222 Plus and it works fine.

Is the monitor OK for the resolution you are using? Or is the correct resolution in the list?

When I first got my setup, even after a fresh installation, I had problems until I manually inserted the resolutions I wanted in Prefs:ScreenMode preferences/Monitorscli

[OldAmigan]

That's correct that the built in video won't display whilst you have a card installed. I'm surprised it displayed on the inbuilt graphics at all!

Try disconnecting from the inbuilt output. You may get a smaller resolution display (1280x768) showing on your main monitor. Especially as you have done a complete reinstall

If not, remove the Radeon, then on the other monitor, go to Sys:Prefs/ScreenMode.
It will open on ScreenMode Preferences showing two tabs - Available Modes and Monitors. Click on Monitors
You should see Radeon if you have Radeon in DevsMonitors. If it isn't there, check in Storage/Monitors and drag it across.
Uncheck 'Detect settings automatically (it didn't work on my setup, so I unchecked it)
At the bottom of the grey box, click Add, then in the bo, enter the screenmodes you want - obviously at least 1920x1200x60 (or the refresh rate for your monitor but should at least work with 60 Hz)