H210 smart switch keeps turning off only in app
We have installed several smart switches in our house, but have ram into an issue with one of our kitchen lights. The light switch appeared to be wired as a 3 way switch, but upon research this might be a Single Pole Double Throw situation? There were 3 black wires connected to the old basic switch. We ended up replacing it with a 3 way H210 switch. The physical switch works fine, but the indicator on the switch and in the app switches back to 'off' after each time we turn it on (but the light itself will remain on). So it goes like this:
Turns light on> app&switch will react as if it's on for a second, then app&switch react as if it is off.
I then have to turn the switch "on" in order to actually turn the light back off.
How can I fix this? Should I instead use a single pole smart switch? If so, how would I connect the 3 black wires? Should I leave one black wire out? Any help is appreciated!