While not a digital key issue per se, we dropped our XM off at out local auto "spa" for a nice wash and detail. We use digital key+, so we left the key card (that we keep in our wallet). This is what we always do, and no problem.
We returned an hour or so later, to find our XM parked in the drop off lane (and blocking other cars). They told us the key card would not work.
We checked and it was deactivated
All we can think of is the OTA software update we did during the night, somehow deactivated the key card. So be aware of this.