Yes, since you are trying to utilize RMS VPN in TAP (bridged) mode while your PC and the RUTX10 are already in the same LAN subnet, this will be the main reason behind the unstable connection you are experiencing.
TAP mode in RMS VPN is currently still in the BETA stage, and at this time it is not recommended for production use due to stability issues. However, if TAP is required for your setup, you may try following the suggestions provided in the relevant thread here: