Q: Is new Memory causing system crash?

If the issue started after the RAM was installed then yes, it is possible you have either a defective DIMM or you purchased the wrong RAM. I would recommend using Apple Diagnostics and see if anything appears.

Using Apple Diagnostics - Apple Support

BTW, do you run any antivirus or cleaning apps on the machine?

Take out the new RAM and put the original RAM back in. If the crashing stops, then you've got your answer.

Crucial is a very good supplier and getting bad RAM from them is rare.  Check to make sure the RAM is securely seated in the slots and test.  If still crashing remove and test as KiltedTim suggested.

If it is the RAM Crucial is very good about replacing.