Mobo killing ram?

Recently I built a new pc my specs are as follows:
Ryzen 5 3600
Sapphire rx590 nitro+
Adata d60g 3200 mhz ram (2x8)
Asrock b450m pro4
Cougar stx 700 something psu( kept this from my old rig, which was working perfectly fine I just wanted to upgrade my system,along with my new ssd and old hdd)
Never OC'ed any component

I set up my new rig with no boot problems everything was working fine for 5 days than I got my first bsod and I thought it was caused by storemi with 2gb ram cache. With further inspection I realised that the bsod had different errors at the beginning but then it always said memory management. When I tried the win10 memory diagnostic tool it showed my ram had problems I narrowed it down to one stick of ram since only one of them showed problems in the test. Didn't give much thought to it and RMA'ed the faulty ram, the new stick came two weeks later and until that I used my pc with no problems with the working stick. I tested the new stick and it had no problems, overjoyed with my now complete system I put in the new stick and used my system with no problems (I didn't use storemi again btw thinking it was the culprit) for 5 DAYS AGAIN and the new stick got corrupted as well. The working stick was in the 2nd DIMM slot and the other sticks were always installed on the 4th DIMM slot.
So I either got so lucky to receive 2 faulty ram sticks and have a story to tell my kids or my mobo definitely has a problem (some people suggested a psu check but I'm rather certain it has no problems since it is about 1 year old and I had absolutely no problems in my old rig)
Right now I can use my pc no problem BUT I am so scared something is going to happen to my cpu and gpu.
I bought the mobo and the ram sticks from a distributor of asrock in my country but that firm is such a problematic firm and I am quite certain they will either not rma the mobo or try to pull a trick on the deal (they've had 240+ complaints in a year from customers).
I'm considering buying a new b450 mobo because I really don't want to be left without a pc in a possible time of lockdown what do you guys think should I bite the bullet and buy a mobo or try my chances with a possibly faulty mobo that worked for 2-3 weeks

Is there any way I can check my mobo without risking the working stick?

I have not touched the bios.

Yes when I first assembled the pc the rams were running at 2666mhz then I switched it to xmp 2.0 (the rams support it) and I was able to run it at 3200mhz in dual channel.

When one of the sticks failed first I checked the bios and it was running at xmp 2.0 at 3200mhz and 1.2V so I cranked it up to 1.35 since the ram Web page suggests to use them at that voltage (I have not tinkered with timings or what not and I only raised the voltage to 1.35 because the official web page suggests it as you might know my mobo supports up to 3200 mhz so I bought 3200mhz rams to have high stability in my system).

My old rig had a r9 270 graphics card but I also used the rx590 on that rig for about 1-2 months before I upgraded my whole system, I had 2 sticks of ram again and I had a fx8320 cpu which has a 125tdp profile compared to the new r5 3600's 60 tdp, I know tdp does not directly mean electricity use but I believe it is safe to say my old rig draw more power

Btw I have been using the ram stick that still works at 1.35V with xmp on at 3200 mhz

The issue is still there lol I am almost sure the same thing will happen if I RMA the corrupt ram again, I need to get to the root of this problem and make sure whatever that is it won't risk my cpu and gpu

so same slot different sticks same problem? I'd go ahead and RMA the motherboard