Bios settings not saving

[GodSlifer02]

Hi! I have an asrock B450m steel legend motherboard with an ryzen 5 3600 and 2x8gb of ddr4 ram. the problem is mostly that every time i shut down the pc the bios settings reset to default, and when it does, the pc won`t post.

when I initially got the problem, i reseated the ram sticks and didn`t solve it, so i searched for possible solutions and i read that in some cases, asrock mb's will only post with 2 sticks of ram if it has xmp enabled, so i entered the bios with 1 ram, activated xmp, saved, got to windows and shut down the pc to install the other ram, i turned the pc once again and it worked showing the 16gb of ram. I ran some benchmarks and everything was normal. When i shutted down the pc, once again it wasn`t posting so i had to do every step once again.

I tried to do a cmos clear/reset but didn`t work.

I replaced the cmos battery (two times) and also didn`t work.

I made a new installation of windows (didn`t keep anything, wiped the disk clean and installed fresh windows from an usb) thinking it may be some software error but also didn`t fix my problem.

Also tried every stick of ram (individually) on every slot and all worked, tried with another ram and had the same results.

Edit: i also forgot to mention, when it doesn`t post (two sticks of ram installed, no xmp enabled) it just keeps power cycling every few seconds. it works perfectly fine when it has xmp enabled