This document is circulating on German social media. In short it is calling for a delivery halt on various B48 engine cars due to a faulty engine part that could cause the engine to fail.
No further info yet.
Google translate :
The bearing of the balancer shaft in the engine may not be robust enough. Effects This can lead to premature bearing wear and possible engine damage. The engine may go out while driving. Affected vehicles According to vehicle selection Measure Engine Replacement Procedure as described in Repair Instructions RA 11 00 050 Removing and installing engine.