@Cyngal77 , if unplugging didn't work, you might try unplugging and holding the power button for a minute. That can drain stored electricity that might remain for awhile (capacitors?).
If that doesn't do it, you might try the so-called "cache clear":
Hit HOME 5 times.
UP once.
REWIND twice.
FAST FORWARD twice. (Clears cache & tv reboots itself. Be patient. It takes 2-3 minutes for the tv to go black, and come back on)
That really does fix problems when nothing else does (but, not always, and sometimes not even for the same problem). It's more than a restart.
There is a pinhole factory reset in the back. you could try that if none of the above works. If I were you, I would tell the initial setup I don't have internet. See what happens with that lightweight version of the software. If it behaves itself, then go to settings>network to create a network create the connection. Maybe it will still behave. If not, then you know more about what's happening.
"People are often amazed at how much we’ve done with the number of engineers we’ve got." (Roku CEO Anthony Wood, Austin Statesman, Oct 4, 2019). "Amazed" is one way of putting it.
