IIssue with Remote access to Plex server

Dear fellows. Please assist with the issue. In the remote access tab in Server settings I get the disconnected error. Although I have 32400 port forwarded (port chech says it is open), also UPnP turned on on the router (Unifi Security Gateway Pro) and the green connected icon with fully accesible state. But the connection drops and I have to click manually to reconnect each time it is disconnected. Earlier everything went smooth, I didn’t change the network configuration.