Display changes resolution when HDMI switched off

I have an RPi4 running LE 9.2.3 connected to an AV receiver. The receiver is connected to a UHD 4K TV, but the receiver will only function up to 4K @30. Since all my content is either 1080@30 or 720@60 I've set the system -> Display -> Resolution to 1920x1080p @60hz.

I also have TVHeadend server and client and sd45vh addons, but I don't think that is a factor with my issue.

What happens is when I turn off the TV and AVR or switch to a different input of the AVR, the display on the RP4 is wrong when switch back to it. usually 1024x768.

I have to reboot to fix this. Is there a setting I can use to keep the 1920x1080@60?

When I had this problem, I looked at the /flash/config.txt and found this setting. I thought it would help.

hdmi_force_hotplug=1

I removed it and am testing it now. I have not had the issue since then, but not sure if this setting was causing the problem?