All started when I decided to put some thermal paste on the cpu.

A day before I had updated my bios which by that time was 0405.

The next day I unscrewed my Fryzen and then cleared the top of the cpu gently and added the paste. Then I started the pc and it was ok.

The problem started when I decided to unscrew the Fryzen again to see if I had put enough paste on the cpu.
For my convenience I removed the memory sticks.
After this when I tried to start my pc I got this error.

I checked the 4 memory sticks one by one in DIMM A1. All good.
When I try to put only a memory stick on D1 ( I don't know if this is right) the message appears.
When I put all 4 memory the message still appears.

I have examined very carefully the memory slots with a loupe for bent pins and I have also opened the cpu to see if there are any pins that are being bent too.
All seem fine.

I have removed all components and all power cables of the motherboard including the battery. I left it for almost 2 hours but with no luck.

I don't know what else I can do.

I sent an email to Asus and their reply was that the RAM kit F4-3200C14Q-32GTZRX has not been tested by Asus for this motherboard and there are no official information about the compatibility.
They told me to check the motherboard with a RAM kit of the Qualified Vendors list.

Is there a case that the update from 0405 to 2101 caused this?
I don't have any other memory to test the slots.

Do you think I should buy another RAM KIT to test it?
I would like to upgrade my RAM anyway.

Any suggestions?

Here is a video from memory slots and cpu