Howdy. I tried searching for discussions covering this but nothing seemed to match my specific case.
I recently upgraded to to Fedora 30 from an older 28 install. Prior to the upgrade I was using a newish Viewsonic monitor connected via HDMI without issue. After the upgrade, if the monitor is connected the system will boot to the point of showing the grub menu but once it proceeds past that I get a flashing cursor for a few seconds and then the system spontaneously reboots. This loop continues until I unplug the monitor or turn the machine off.
If I disconnect the monitor during boot and then reconnect it once I can hear the box starting to process startup scripts everything works as expected and I can log in without issue.
I have looked through the BIOS for anything HDMI related but have not seen anything obvious. Any suggestions on what could be causing this and why it started with Fedora 30?