@KenV99,

I will be honest that I have faaar more experience with Tapo's version the S515 to start.

At any point, has one of the switches completely lost power, from a combination of on/off states between the two?

As long as your wires are all connected properly, and verified to be funtioning as intended, i would look towards three things:

1 - Pair the Switches, without them being paired, its possible that one is interfering with the normal operation of the other.

2 - Your traveler wires may not go directly to the other switch and may instead have the light between the two switches.

3 - Double Check all your wires, if you have done any renovations or electrical work its very possible that a wire got repurposed. Also check that there is no power coming across your ground or neutral wires.

In case it is something with the device itself, you should consider getting in touch with our support team who are better equipped for things like that. I will say just from personal preference, take a look at the Tapo S515, even if just for future installs. It was our first venture across both brands into providing a much more streamlined installation and works in multiple setups.