Just thinking out loud. Ive had 2 X5s, perhaps 85k total miles, 5 years...never had a single electrical module fail. You've had two in one vehicle.

One therefore thinks about a common fault trigger. "thinks" as in considers or wonders. Still you fix what is broken, but if you get a third issue you might look at some sort of causal factor. Voltage spikes, regulator, grounds, etc, etc.