Hi Sascha,
Are you facing this error in all your systems or in the production system only? Because that reminds me of a similar problem that we faced (although it was not limited to BP address) when our basis team decided to add a new application server to ECC... but didn't realize that the configuration was not complete, and everything sent to this AS was just lost (which made it look like some "random" bug because you never know which application server will process your data). As soon as the new application server was "removed" (i.e. was no longer available in tcode SM51), everything was fine again.
Regards,
Nicolas.