Whirlpool Duet washer WFW9200SQ02 - When washing, the first load it's fine, but if I put in a second load right after I get the F25 error code only on the rinse / spin cycle. I can let the machine set for about 45 minutes and complete a rinse and spin cycle, or if I wait for about 45 minutes to start a second load it is fine. I have replaced the MCU, I have checked the tachometer resistance and it was 117 which is good, but seems like temperature is playing a role in this, is this the motor or the CCU? Which would be the best to replace next.

From what you described that is going to be the motor, it's overheating and shutting off in overload and once it cools its able to complete the cycle. The motor new is about 350-400 but you can get a good pre owned motor that has been tested and in working order from the link below for 65 + shipping.

https://prismparts.com/products/for-whirlpool-duet-washer-drive-motor-pp4481106?_pos=2&_sid=bb5f0234d&_ss=r