I have the excact same issue and I tried changing the propteries reinitialization and preferred network provider without luck. I really hope the developer team will fix this anoying problem.
I think I know what is wrong. This is probably caused by "Reinitialize TVService" PowerScheduler setting. Can you try to disable it and see if that fixes the problem?
What happens exactly?
Did you try to changedthe "preferred network provider" from "generic" to "DVBS"?
For me it fixes the tuning instability when the reinitialization is unselected.