iMac 2020 crashes

Have you run Disk First Aid?

Have you reinstalled the OS yet?

We need to see what all is running, a report from this will not display any personal info...

EtreCheck is a FREE simple little diagnostic tool to display the important details of your system configuration and allow you to copy that information to the Clipboard. It is meant to be used with Apple Support Communities to help people help you with your Mac. It will not display any personal info.

https://www.etrecheck.com/

Pastebin is a good place to paste the whole report if you capture the URL while there…

Workable but harder for me to work with...the Note tool on the bottom of this editor's toolbar, as shown in the image, to copy and paste the output from EtreCheck. In a Reply before you click post, look for this to add longer texts...

Oh. missed that... Corsair RAM, only use Crucial or OWC, Macs are picky...

Memory Upgrades for 2019-2020 iMac 27-Inch - Up to 128GB (macsales.com)

Does the iMac crash with only the origin RAM modules installed?

Where did you get the 3rd party RAM?

I only have 2 guesses after reviewing that...

F-Secure

Hardware issue

Hmmm, has it still been behaving with the old RAM, I've necer had bad EAM from OWC & only one bad RAM from Crucial, I generally don't mention Crucial due to that.

+1 on using Crucial memory.

Mac computers are sensitive to memory, and even if Corsair memory worked previously, it could be causing an issue now.

Jack