I did an install of 20.08 ARM xfce on my Rpi4. After initial setup, it boots normally to the desktop but there is black space on the right side of the screen as if the desktop does not extend to the actual edge of the screen and I do not know how to correct it.
What resolution does your monitor have?
I believe the default is 1920x1080.
I got a Dell 19"wide so it’s 1400x900
I’m not well versed in display settings on the Pi’s, but @Darksky might have ideas when he wakes up.
Try this in your /boot/config.txt:
hdmi_mode:0=47 hdmi_drive:0=2 hdmi_group:0=2 hdmi_force_mode:0=1 hdmi_ignore_edid:0=0xa5000080
Also check in your DE’s Monitor Settings that it is set on 1400x900
Also if no change try rem’ing this line in config.txt like this and reboot to see if there is any diff.
I attempted these settings with no success. After a reboot, the said monitor would not display the screen at all. After of which I have to reimage the drive (I use an ssd). Referenced a few pages for information regarding the RPI4 specifically on Raspberry’s site. I was not able to implement the changes stated in the articles. I resolved my issue my swapping out the monitor. It is utterly not useful to not be able to post links to information regarding troubleshooting issues on a forum for troubleshooting issues.
While I do agree that it’s not practical, it’s set in place to limit the amount of spam posters, as far as I know.