+1 I think you have missed one of the elements in the firewall somewhere. Or that you need to handle the firewall slightly differently.
For example, when I installed the Control:PC app on my PC my Norton firewall twice reverted to AUTO on all Meridian/Sooloos programs. AUTO was not enough. I had to manually set to ALLOW on all programs and also do that twice with a reboot for it to stay set. No idea why. I did wonder if there was a sequence involved but left it at that.
As G997 advises above, turn it off for a brief time and see what happens. That'll help narrow it down.

Rgds,
Nick