I've noticed that with my former 'TE, and about every other car I've owned will not sit level from time to time. I have also had a loooooong series of new problems that arise when or just after a repair session. This has happened both when I've worked on them and/or had them worked on. The moral being that no one thing ever goes wrong at once. Problems don't take turns, they compete for attention. Bastards that they are.
If the work was done by a MB dealer, complain loudly. Complain to 1-800-4-Mercedes. Complain to the BBB, the attorney general. You might get some good will from MB as a consequence.
Hope it works out! I get the feeling that your 4-matic is like my former one, in that it is high maintenance…..
Best of luck!