docker not exposing the port with network host

--net=host option

This option bind the virtual NIC of the container to the host physical NIC (by giving full access to local system services such as D-bus).

When this option is used every program that request a network socket will be granted one by the host from the physical NIC. Your service will then be using the 5555 port as expected.

-p 5555:5555 option

This option bind (through iptable-like mechanism) the network socket containter-ip:5555 to the network socket host-ip:5555.

---

In other words

It seems, IMHO, a bit illogical to use them both. If the needs is to publish the containerized service to the socket host-ip:5555 then the cleanest way is to only use the -p 5555:5555 option.