Thanks for your help! My answers to your questions below:
"When you're saying "connection stops and don't restart", you're meaning connection between TRB and device which is connected to TRB's LAN port (with IP 192.168.2.211)?"
I’m trying to etablish a connexion between a (remote) software and the 192.168.2.211 device via dns hostname and i need to use 10002 and 30704 ports. When i’m connected to USB, the connection is etablishing, but when i disconnect USB port, the connexion do not etablish.
"Or for example, you're also unable connect to TRB WebUI via DDNS domain?"
Yes, unable too.
"It looks like TRB also have public IP address, if you would connect to TRB WebUI and navigate to System -> Administration -> Diagnostics and Ping LAN device's IP (192.168.2.211) will the pings goes through?"
Yes ping is OK
"Also how about TRB configuration via Ethernet port? Are you able connect to TRB via Ethernet port and configure it?"
Yes i’m abble to connect the TRB by ethernet port for config by WebUI.