A note for Teltonika programmers about a nasty bug in the RUT firmware (tested 0.7.6, 0.7.10, 0.7.12).
Port forwarding from OpenVPN to the LAN only works if you leave LAN subnet 192.168.1 (and possibly the LAN ip-address to 192.168.1.1, at least this worked for me).
If you happen to use another LAN subnet, your port forwarding will miserably fail (tested with port 502).
Clearly somebody has hardcoded something, instead of proper variable using. Pls chk and fix.