Additional ram makes my iMac restart...The ram is good.

It sounds like you may have 4 good modules, but not all 4 are getting fully seated in the slots.

Note that the previously unused slots will take more force to fully seat modules in them.

Try this, install the factory modules in the previously unused slots and install the new modules in the previously used slots.

When installing modules, lay the iMac face down on a flat surface covered with a soft towel.

If the modules install in the bottom of the iMac, push firmly on each module with both thumbs.

If the modules install in the back of the iMac, push firmly on each module with both index fingers.

What is the model and year of your iMac? Where did you purchase the additional RAM modules and who was the manufacturer?

It looks like the two new modules and not quite the same as the original and are incompatible when used together. This was the case with 2020 iMacs and OWC (MacSales.com) modules. They would not work together.

If you can return the two new modules and replace them with modules from Crucial.com. Crucial is a well known supplier of Mac RAM and guarantee that their modules will work in the Mac models they are intended for because they test them in each model.

OWC RAM models are also exceptional for Macs except for the 2020 iMac. If your model is not a 2020 iMac you can get the modules from either vendor.

There was also the same/similar problem with 2010 27" iMacs - third party ram would work as long as you did not go to the maximum. Not sure that one was ever resolved unless you just installed less RAM ( at the time, the max was 16 GB;I did 12 and it was fine).

To be honest, I don't know what the solution would be - if there is one. You already did all the troubleshooting; might be good to contact Apple support just so there is a paper trail of the problem - make sure you tell them everything you tried and mention the older models with a similar problem at the time.

It seems that programs, you install, bring in commands that run in the background of the computer,

It would be beneficial to the community is you identified the apps the caused the problems so those of us in the forums every day can better help others.