@QcDbz 

Good day,

Thank you very much for your time and patience.

Sorry for the delay.

Did both light used to be controlled by 3-way switches?

If yes, you could replace the one dumb switch used to connect the neutral wire by HS210

https://www.tp-link.com/support/faq/2009/

Q: What if only one of my switches has a neutral wire?

A:  After examination, if you find that one wall switch has a neutral wire bundle but the other one does not, you may still be able to use HS210. While HS210 is designed to work in a pair, you can replace the wall switch with the neutral wires while leaving the old wall switch in place. If the neutral-less wall switch is very old, pops when actuated or has any other signs of age, you should replace this switch with a new, standard three-way switch to ensure reliable performance. It should be noted that this is a non-standard configuration for HS210 and results may vary.

Thanks a lot.