Sounds like a wiring problem, that the black wires aren't what you expected. You might try tracing them back to confirm one really is line in and the other goes direct to the fixture. It could also...

That's often a wiring problem, either an incorrect white (neutral) wire connection or trying to use the switch in a "power through fixture" circuit.

It's just a simple relay, no different than an ordinary switch. There's nothing special about the power through it. If you're flashing the lights the bulbs may not be able to handle that, if not I'd...

No further posts on the old forum, no new section for smart home in this forum. Is that it then, no further support for smart home devices? Are they EOL? Too bad, they're actually quite good relative...

Sounds like a wiring problem. If the switch is rebooting (flashing amber) after you turn the switch on the neutral wire is probably incorrect.

...or finish the migration to this one. An occasional answer from technical support would be welcome too.