Docker nginx 2 network adapetrs

I have such a problem. I have a server with two network cards, local and external addressing. I installed docker, ran portainer and nginx and I have access via an external address, everything works, but when I am in the local network and I punch in the external address, the connections are reset and I have no access. There are no blockages in the network itself, because other servers in the same external subnet work. What could be wrong