Another eBay bad buy, or was it?

I had 2 8GB and 1 4GB DRAM sticks in my pc.
The 4 GB was only single channel so I bought another off ebay.
Plugged it into pc and no boot.
So cursed ebay and the bad seller.
So had a look online for more memory.

I then decided to take a step back and try the new 4gb without the old one in and that booted.
So popped in old one again and after a while it booted too.

I had forgotten that if pc memory is changed the pc goes through a memory training routine and takes a lot longer to boot.
So unfairly cursed ebay and the seller.
Left some nice feedback on ebay.
 
The delay is extreme on Ryzen 7000 boards with DDR5. A board equipped with 128 Gb (4x32 Gb) and the first AGESA Bios took about 40 minutes at first boot to train the DDR5 memory channels. This is before screeen and devices initialization. I even separately exchanged and returned the mainboard, the Ryzen 7950x CPU and the RAM sticks before this behaviour started to be documented online, then I bought everything back (at lower price, so at least I did not lose money) and just waited almost an hour - the screen came up to BIOS setup and everything was fine. The first AMD AGESA Bios was so bad. Now , after a BIOS update, it takes about 6 minutes from pressing the power button to the screen turning on. This is common on servers, I once had a few maxed-out Dells with 36 RAM sticks that took even more to start the boot process, but it is the first time I've seen this behaviour on a PC platform.
 
By installing 4 DDR5 sticks, the RAM is lowered from 5200 to 3600. It is then possible to use slightly cheaper memory sticks rated at 4800 instead of the usual 5200. Unfortunately the maximum DDR5 stick capacity is currently limited to 48 Gb: 4 sticks are a necessity when more than 96 Gb Ram are required.