Is this a new set being set up for the first time, or one that previously worked?
MAC address of all zeros indicates no connection between the TV's network circuits and the rest of the TV.
I'd suggest doing a Factory Reset and setting the TV up again from scratch. If the MAC is still reported as all zeros, take it back to where you purchased it if you still can.
Otherwise ,,,
TCL support:
https://support.tclusa.com/televisions
1-877-300-8837