issue with surfaceFieldValue in v1912

I noticed an issue with surfaceFieldValue combination with dynamicMotionSolverFvMesh in v1912. The function writes out the header for all time steps into the dat file.

I upload the case as a zip file. case.zip

If you run it in v1812 the dat file in postProcessing is fine. If you run it in v1912 it writes out the header in each time step, however if you change in dynamicMeshDict "dynamicMotionSolverFvMesh" to "staticFvMesh", the output is fine again.

Please consider, that the case is a constructed one for this problem, so it has no real physical meaning.