I have a PC with an Asrock B450M Steel Legend motherboard and a Ryzen 3700X CPU and I occasionally boot Ubuntu from the live DVD. Unfortunately it looks like Ubuntu is corrupting the BIOS though. After rebooting from Ubuntu the machine will hang at the POST screen and refuse to boot or enter the BIOS unless the BIOS is cleared with the CMOS jumper on the motherboard. This happened several times with Ubuntu 18.04. I then switched to Ubuntu 19.04 and updated the BIOS to the latest available and unfortunately it's happened again. This only occurs after rebooting from Ubuntu and only some of the time. Is this a known issue?