I have purchased and installed over 60 Kasa switches in my house. 

Most are single-pole, some with dimmers, and 4 pairs of 3-ways.

All my switches are working correctly except for the 3-ways. The 3-ways will work ok, but after a while (a few weeks to a few months) - they will slowly start to fail. They will get into an endless restart loop. turn on and off. This will go on for a few days till they stop working completely.

This happened with every single 3-way switch I installed.  My current fix is to just buy a new one and replace the dead ones - but I will need a fix for this as I've bought over 10 pairs so far and I will may just stop buying them and switch to a different product.

Any idea what's going on here? Is this just a defective line of product ? 

Worth noting - when they fail, it`s usually just one of them. Not the whole pair. So when i`m installing a new switch, i`m just replacing the dead one and keeping the other pair in place