Greetings,
What are your system specs?
What GPU are you using?
Most cards from 2016 or later are UEFI compliant or have a option to be flashed to compliance.
The CLR_CMOS should work. Start pulling stuff, the GPU, all but one stick of memory, any connected devices., HDD or m.2.. "shake it up".
Remember however, I did say in my first reply that 5 beeps indicated a CPU issue. At this point, you may want to remove the CPU and check the socket for bent pins as well since the system is not behaving normally and is not responding to normal (standard) reset.
Getting stuck during POST (VGA LED on). Failed CPU pre-initialization checks. This means hardware. This could happen because you have a "KF" processor, but you need to do more troubleshooting.
Something isn't right and your inability to reset the BIOS is looking like another problem.
ALT+F10 at POST will give you the ability to overwrite the back up BIOS. READ THIS I do not recommend you do this. It might be helpful however to see if the option comes up. You can cancel out of it using the "x".
If you don't see this BIOS back up option, I don't think your issue is related to the settings you made...