Sorry for your problems and welcome to the forum.
The Adventure Wagon partnership is brand new so, no, we haven't seen other similar such issues.
Because it's a Mercedes issue you will have the best results going up the Mercedes complaint chain. Winnebago pretty strictly differentiates between their product and the chassis manufacturer.
There is a dedicated Sprinter forum that has an RV section and they seem pretty helpful over there.
https://sprinter-source.com/forums/index.php?forums/5/
Adventure Wagon has a help line and perhaps they can be of some help:
503-427-0140
Mon-Fri | 8am - 4pm PST
That Sprinter forum I mentioned has a driveshaft issues thread going:
https://sprinter-source.com/forums/i...hreads/129331/
Best of luck and hope everything gets worked out as soon as possible.