I have the same issue with the Vive Pro 2. I have the basestations 1.0 from the original Vive in use. With the old Vive everything works perfectly!
With the Vive Pro 2 the display is going to be grey after a few seconds with a blinking symbol when i start SteamVR. Also the basestation-icons dissappear. It takes some time to get a connection back, then repeating losses....grey lenses all the time. It says the Headet is not sending signals / cannot see the basestations...
The Vive Pro 2 is unusable with this issues for me!
Computerspecs are nearly same as yours. Only the newest and strongest hardware.
I reinstalled everything again and again. I now use the newest hardwaredrivers, firmware, bios, etc.... SAME ISSUES.
I CAN NOT FIX that issue with tightening some cables like you.
I preordered on 16.05.21 and it came shipped on 18.06.21. Now I want to send it back.
Its not worth the time (and money) I invested already with useless bug-searching.... I will go back to the old Vive until something better comes out.
I am really pissed about all that as you can imagine. It would be a nice product if it worked as it should, but - "Computer says no" and so I do.