Deformed Geometry + Chemistry

Hello,

I am working on a model which describes a chemical dissolution process. My idea was to use the chemistry module which calculates the kinetic data of the surface reaction and couple it with the deformed geometry and transport of diluted species modules. The chem and tds module with flux boundary conditions communicate just fine. But there seems to be a problem with the dg module as the solution does not converge. It does if I put some number into the Prescribed Normal Mesh Velocity box. What could be the reason?

Thanks