As much as I tested it, it worked well, but I contacted plugin’s author and he said that there might still be some issues with it and that he will create a plugin/fix for bbPress in near future.
I solved the issue with following plugins:
Multisite User Sync
ThreeWP Brodcast
For anyone having the same problem.
I solved similar issue with following plugins:
Multisite User Sync
ThreeWP Brodcast
