Question Can't utilize RAM at full speed since switching to 13th gen

[reapzstar]

Hey there!

I'm currently using 2x16 Corsair Vengeance RS 3600 CL18, running at only 3200, as for some reason my CPU(?) doesn't support any higher.
I'm unable to boot into the system if the RAM is set to anything higher than 3200 Mhz.
Before having switched to 13th gen, the RAM worked just fine running at full speed with XMP on, that was with an i5 12400f
The day I switched out for the 13th gen, it didn't work properly.
I contacted ASUS support, they escalated my case to their highest possible rate and came to a conclusion that I'm unable to use my RAM at full speed because it's not officially supported.
Frankly, I call bulls*it.
My question is, do I just get a new motherboard that hopefully isn't utter trash like this one, or do I get some new RAM(even though that one I looked at also isn't supported) or what do I do?

Any suggestions?

Specs:
i5 13600KF
aforementioned memory
ASUS TUF B660M PLUS D4
MSI RX 6800 XT
Sesonic Prime Ultra 850 Titanium

 

[rgd1101]

latest motherboard bios?
what exact happened when you turn the xmp on?

 

[reapzstar]

It is the latest, yes, 2014 to be exact.
When I turn it on it defaults to 3600 Mhz, the computer restarts and won't boot.
The motherboard indicator LED will stop on orange, the do the cycle again, red for like 1 sec and orange for like 3 seconds and just goes on in a loop.
Only way to boot again is by clearing the CMOS. Also, manually lowering the Mhz from 3600 to 3200 before exiting and saving, then it boots without any issues.