Switch gets power, wiring is good, but it doesn't turn the light on
I successfully installed one dimmer in a gangbox of 3 dimmers and a toggle switch. It linked to wifi fine and worked as expected. After installing a second HS200, which also worked fine, the first switch stopped controlling the light. It gets power from the common wire and all the wiring seems intact. The app and the the switch seem to think it is controlling the light in that you can make adjustments and the lights signifying the intensity of the dimmer work and can be adjusted. However the lights don't turn on.
Again, the wiring is fine. Thoughts?