Hello Ahmed,
I currently have the same problem, with another RUT955.
Both Routers are the old Version.
Firmware: RUT9XX_R_00.06.07.4
There are no routing rules created. Only the firewall rule, for remote web access.
Connecting the similar IP-Networks doesn't seem to work. Unless I'm missing a rule.
I changed the network configuration, so I can avoid this problem. It still would be interesting to know what exactly causes this.
Best wishes,
Nico