I've been using ZorinOS for a while, I recently did some updates and turned it off, but today when I try to switch it on, it keeps redirecting me to the BIOS screen. SSD does not appear on the BOOT screen. When I want to add a new BOOT option, I save and close the BIOS, but it is not added, it is deleted directly. It happens the same way with USB.
I can't select the boot method at all. The USB stick and SSD are not visible. I select the path with Add New Boot Option, save it, and restart, but the BIOS screen appears again and it is not saved. The date and time are correct on the BIOS main screen, but is it possible that the battery is dead?
This is a bit tricky:
Sometimes it could help to load default settings or make a CMOS reset but if you have changed things on your system (replaced HDD with SSD, switched from legacy to uefi...) you have to check the settings afterwards if they are set correctly. There is the danger that it won't boot.
If you have made an update for your firmware that flashed the BIOS this could also have reset the settings in your BIOS.