After work, I'll confirm but suspect the fan is not coming on a soon as the A/C button is on. The fan does work when engine temps are normal. A/C starts to cool as soon as it's moving. I'll turn on the A/C without turning on the engine.

I don't think the fan always runs from AC on. Mine didn't used to but my fan was broken and recently replaced.

I know with other cars I've had, the aux fan woukd come on at a lower ECT when AC was on but just 10-20° lower than when ac off.

With the engine off and A/C on, the fan didn't start. I may try the craziest fix found on YouTube. Why not? A BMW tech confirmed it!
https://www.youtube.com/watch?v=Xb6_wKLOxnU
Low and high pressure switches work or the system would be toast. The guy went through 3 fans and a switch. :wow: I have the tools to evac and refill. High side pressure it at it's limit for ambient temps. If any atmosphere is present, the efficiency is lowered.