Errors on the patches between processors with buoyantBoussinesqPimpleFoam

Hello,

I am running a case with buoyantBoussinesqPimpleFoam. I get a good solution when running in serial, but in parallel there is strange behaviour on the patches. This behaviour is absent if gravity is set to zero. I got the same behaviour when running in OpenFOAM 5 and 3, on different computers. Attached is an example case reproducing said error.

Regards, Sara boxParallel.tar