I just got my new 2019 iMac and ordered this Crucial memory:
Crucial 32GB Kit (16GBx2) DDR4 2666 MT/s (PC4-21300) CL19 DR x8 SODIMM 260-Pin for Mac - CT2K16G4S266M https://www.amazon.com/dp/B07TKZKPJV/ref=cm_sw_r_cp_api_i_S6F-DbSW5EFTF
I tried it every which way and my computer won’t boot up with it...I just get a black screen. It’s supposed to work according to Crucial. Any ideas?
I have the same sticks and have had no issues with them in my 2019 iMac. Are you sure you're snapping them in all the way?
edit: Oops, just realized that post was from last year.