Modbustcp and Node red under docker

Moved my node red from Ubuntu server to Docker with macvlan network driver (Node red has own IP address) same network, but Node red under Docker can't "talk" with Modbustcp device, running fine under Ubuntu.
All network communication works as expected under Docker, except Modbustcp. Even finicky Wemo devices discovered without any problem.
Tried to open port 502 (Modbustcp port) under Docker but Node red still won't "talk" with the device.

Does anyone have experience with Modbustcp + Nodered + Docker?

Thanks.