buoyantPimpleFoam with thermalBaffle1D: strange temperature decrease
 

I took the pimpleDyMFoam/propeller tutorial and added a 1D thermal baffle with Qs uniform 1000;
I launched the analysis with buoyantSimpleFoam: it converges after 1189 iterations and the maximum temperature as expected increases from 273K to 339.4K.
Then I took the 1189 time as starting point for buoyantPimpleFoam with the propeller stopped to see how much the temperature increases when there is only natural convection. But the temperature in less then 0.2s decrease from 339.4K to 328.4K. I wonder if this is linked to a bug?

I upload the files here:
https://www.dropbox.com/sh/gj602mpsi...E8bKzHkVcSS9aa
What I did is:
- took the pimpleDyMFoam/propeller
- added in front of the propeller a 1D thermal baffle like in the circuitBoardCooling tutorial
- switched from AMI to MRF approach to be able to launch it with buoyantSimpleFoam
- took the last time directory of the converged analysis and use it as starting point for the buoyantPimpleFoam analysis
- commented in fvOptions the MRF subdictionary (propeller not rotating)
- launched buoyantPimpleFoam for 0.2sec, temperature will decrease from 339.4K to 328.4K.

do you have any suggestions to solve this strange temperature behaviour?