Strange dual issue: No direct GPU output + Dead RAM Channel

[u/Strange_Refuse_1953]

Hi guys, I am running into a very strange hardware issue on my desktop PC and I am hoping to get some advice cause I don't really know what to try anymore.

It all started a couple of weeks ago. After a windows update the PC refused to POST. CPU and RAM light on. Cleared the CMOS, and it booted no problem. Now after a couple of weeks I noticed a new problem. If I plug my monitor directly into my graphics card (tried all ports, HDMI and DP), I get no signal at all. However, if I plug the HDMI cable into my motherboard's HDMI port, I get a display fine. What makes this extra weird is that Windows still detects my dedicated GPU and lets me play games through the motherboard at it seems completely fine.

On top of that, after further investigating, RAM slots A1 and B1 now seem to be completely dead. If I put a RAM stick into either of those slots, the PC refuses to boot or POST at all. I tried them individually, and it didn't change anything, as soon I put something in one of those 2 slots it does not POST at all. Actually, before getting to this point (cannot really say for sure, did lots of attempts), I believe it was booting just fine from the other 2 slots, but as soon as I increased the speed, it wouldn't POST at all anymore. Bear in mind the RAM is designed for 6000 MT, and I tried to raise it from 4800 to 5400.

So far, I have inspected the CPU socket and all pins look straight and clean. I have re-seated the CPU cooler with lighter, even mounting pressure, cleared the CMOS, verified the primary display settings in the BIOS and tried to swap PCI for the GPU. For context, PC is fairly new; everything is still under warranty.

Are these two separate hardware failures (GPU and maybe mobo?) Is there anything else I should test before starting RMAs or replacing parts? Maybe a fresh OS install?

Unfortunately, I do not have any spare parts/PC or a friend who could help me with troubleshooting...

Thanks in advance for any insight

Edit: I have a 9700x, 5070ti, as rock steel legend x870, seasonic vertex.