Ryzen 7 6850U - Heavy flickering after RAM 1x16=>2x32 upgrade under Manjaro

Greetings. Feel free to move this if I landed in the wrong category.

First - The laptop is dual-boot and the problem isn’t present under Windows 10. I’ve run few tests under Windows, under Manjaro and from USB - nothing in the memory or GPU seems to be physically affected.

The CPU is Ryzen 6850U + 680M inside a HP 845 G9 laptop.
Win10 is there for a witness. The Manjaro is what I will be using.

  1. The laptop works normally after removing from the box and installing both OSes. At the moment it will mainly be used with two TVs, one with a regular HDMI cable, the other with a USB-C => HDMI cable. It recognizes them perfectly, the profiles (only 1 or 1+2, the laptop screen is switched-off in both cases) are working perfectly. No worries.
  2. The One Sunny Day comes when the “old” RAM 1x16 gigabytes (SK Hynix) is removed and 2x32 gigabytes (Crucial) are installed.
  3. Under Manjaro, the two screens (TVs) that the laptop is driving, start flashing white. From time to time they remain only in white. The mouse is visible and moving normally all the time, like I have some kind of sheet stretched over everything else. Sometimes only the main screen stays/flickers in white and the second one is ok. All this while the built-in screen of the laptop is turned off. Sometimes I manage to turn it on and the infection jumps there too.
  4. Under Win10, the flashing is gone.
  5. When trying to record the situation with recordmydesktop, the symptom does not appear on the replay through the file.
  6. When returning the old RAM, the problem disappears. When inserting only 1x32 RAM in either of the two slots, the problem does not return. It is only present when the two slots are full.
  7. After reboot, the problem is 50/50 until the machine turns off the screen after a certain time, or if I manually change the profile from 2 screens to one, or vice versa.
  8. GPU and RAM tests under Win are silent.
  9. Self-test with PassMark MemTest86 10.2, recorded on USB is also silent.

Thanks for any questions and ideas, except for staying at 1 slot 32GB because that’s how it works now :face_holding_back_tears:

There is a thread at freedesktop_dot_org (titled " Sporadic flickering glitches on Ryzen 6850U, Radeon 680M"), that I am following and can’t link here for some reason, but I am not keeping close track if there is development anywhere else. I have some sleep catching up to do.

Also I have two video examples, which I also can’t link here for some reason. YouTube uploads. Perhaps on DM if anyone is interested?