Try a different outlet, maybe closer to the router - they can be a bit susceptible to line and RF noise. Since you've had it connected before you know your router is fine - try to avoid changing any...

For symptoms so strange you're probably better off contacting TP Link service directly rather than waiting for them to help here... if it's not a usage error it sure seems unlikely to be something...

You can't disconnect them from the LAN if you want to run a schedule, they need access to NTP servers to determine the time of day.

That sounds a bit odd, the TP Link setup SSID is open and no password needed. The password you need is to log into your account in the app itself.

Sorry to restate the obvious, but maybe your password is incorrect? Did you try resetting it in the app?

I think if it's blinking orange it's having trouble connecting to your wifi and doesn't need to be reset. Maybe try relocating it closer to see it that helps.