I do not understand your network setup. The settings I am aware of are:
Code
internet
|
| public Internet address
router
| local network (192.168.x.1)
------------------------------
| | |
OMV Win10 Smartphone .....
(192.168.x.2) (192.168.x.3) (192.168.x.4)
Internal network is an example only.
If yuor router has LAN ports, which are different, can you tell me how the config is, What kind of router is it?