I just installed a new TGCL-153PH-WH. The lights flicker at full brightness. It is a switch that controls outlets with lamps plugged in. The switch is on a 3 way circuit. There is another same dimmer on a different light on the same circuit breaker. On lamp has an incandescent and one lamp has an LED. I tried unplugging one lamp at a time. Each lamp flickers. Possible problem/solution?