Here is the diy on fixing the AC flicker on 2 and 3.
https://www.mazdas247.com/forum/showthread.php?123819018-How-to-Permanently-fix-the-quot-no-A-C-on-fan-speed-2-3-quot-problem
I've had this same issue with my second pro5. The problem with mine was the battery terminals. I was using the black and red coated ones. Car ran fine after I swapped them out with new ones that weren't paint coated.