Docker access from host OpenVPN

Dear all, I'm quite new to OpenWRT. First of all sorry for my poor English, I hope you could understand me anyway.
I spent some time studying and I've been able to setup quite complex configuration on a fanless router mini-pc. Now I have a problem I cannot solve. I need an expert help.

  • The situation -

I installed luci-app-dockerman, set up a couple of dockers in bridge mode: everything works perfectly. I'm also using a OpenVPN setup to the host unit (the router itself, no docker).
If I'm at home I can connect to each docker to their assigned ports (i.e. 192.168.3.1:8765). If I'm connected remotely via OpenVPN, I can connect to my LAN, and also to other defined LAN2 (some iptables rules here), BUT I cannot connect to dockers.

example:
@home: I can open 192.168.3.1:8765
@remote via OpenVPN: I can connect to the router 192.162.3.1, I can reach each PC on my lan, I cannot reach 192.168.3.1:8765 (docker)

I think it is just an IPTABLE configuration problem, but I'm not enough advanced to solve this. Could you possible help me? If you need more infos I can provide them. Thank you