My 2013 X6M a/c does that occasionally, not as frequently as you state. Usually due to some combination of windows or sunroof open and cold air outside. I think it's a programming glitch. Can't reproduce it so I haven't taken it in for this. It's happened less than 10 times in 24k miles.
Never had the speaker thing happen, but one time I started the car, and the iDrive screen went red then blank. IDrive worked when I randomly pressed to change from radio to media, but the screen was off. Restarted the car and all was fine, never happened again.
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