Bug particles traces


I encounter an issue with particles traces which goes into the model without going out of it.
Can it be a bug ?
I think of a boundary issue but I did as i was being told and others solutions seems to do not be fit to the context.
Thank you

It is a stationary rotating turbine indoor, therefore can’t apply the rotational wall and keep the MRF but then the issue occurs and looks as you see on the picture (contrary of the rotational wall where it works).