Hello
I made some tests. Took brand new RUT955, 06.08.5 and 06.08.6 are working fine. Clean installed 06.09.2 and reconfigured is failing the same way, port will be opened but no communication with client device.
After downgrade from 06.09.2 ->06.09 or 06.09.1 will get TCP error 10061. All had exactly the same config. It is affecting also the RS485. We do have one device over RS485 and connection was lost after FW upgrade.