Hard to say without seeing the layout in person... Generally aren't the bathroom lights on a separate circuit from the outlet GFI? Often the hot (and neutral) are daisy chained in a box, so if a...

Definitely a wiring problem. The single pole switch is a simple single pole relay that replaces the old switch. Line in powers the switch (through neutral) and is switched by the relay to load out....

Sorry for that :(. The wifi doesn't fail all that often though so it might be worth trying a few more things. If it's not flashing after setup it may have completed but your phone re-connected to...

I still think you should contact service directly :). It suggests corrupted firmware and I can't see help coming from this forum... Have you tried examining the settings or connecting from a...

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...