1998 Mazda 626 4l A/T: Electrical problems or failing transmission?
 

Hello All! New here!
"Ivan" has been in my family since the very beginning. Just passed down through various family members. He's now in my driveway, with @190K miles, and on his 3rd (remanufactured) transmission.
So...
I've been having symptoms with "Ivan" suggestive of low ATF, but Ivan's not low on ATF, and the ATF fluid looks good (changed October 2019). I did have a cooling system issue back in September (broken overflow and bad seal on water pump), which I repaired. That being said, I know that any excessive heat wasn't good for "Ivan", and particularly his transmission.
Thus, the slipping, stalling, and sluggish acceleration would seem to be an indication that SOMETHING in "Ivan's" transmission is in the process of failing.
Right?
But the stalling only seems to be happening when I am making sharp turns, where the PS will lock up and my bluetooth cigarette lighter plug-in will completely reset (1 out of 4 times). It's almost like something is shorting out the ECU, and "Ivan" can't recalibrate himself before another short occurs.
I say this because after replacing my water pump, "Ivan" recalibrated, and was running REAL good for about 7-10 days.
Where do I even start?
My Dad is an EE, but electrical meter gauges trip me out.🤣
Thank Y'all in advance for any thoughts/ideas/suggestions. ✌