Thank you very much for your answer.
Unfortunately I have limited linux knowledge, and I do not know how to do what you recommended.
Today I tried App LibNetSwitch presented here >
https://forum.samygo.tv/viewtopic.php?f=75&t=9692 . The TV started on Wired connection (even I had no LAN cable connected to LAN port). I changed to Wireless connection by Remote control in TV Menus and tried Yotube, and big, big surprise: it worked fine! Tried also FTP,Telnet connection and they worked fine, so root was OK.
After that, I powered off the TV, connected a LAN cable to LAN port, and powered TV. TV started again on Wired connection, and I tried Youtube and it worked also. Checked FTP,Telnet connection and they worked fine, so root was also OK.
So this library LibNetSwitch is doing something good for using Youtube, HBOGO and others, but TV starts every time on Wired connection. Can I do something to load what LibNetSwitch do, but to automatically connect on Wireless connection on startup of TV? I mean like a command line to automatically switch to Wireless connection after LibNetSwitch is already loaded?