Insteon toggle linc dimmer only responds to "increase brightness", not to "turn on"

Hi,
I’m part of the recent Insteon shutdown migration to Home Assistant. I have Home Assistant’s OS installed on a raspberry pi system. It is cable connected to a Orbi home mesh system in our house. 6 other Insteon devices and a 2245 hub seem to behave correctly. This one in-wall toggle linc dimmer switch will turn off when commanded by Home Assistant but does not respond to the turn-on command. It does however turn on when commanded to increase switch brightness. This works OK for automation purposes but does allow me to turn the switch back on remotely with the iPhone software button.
Thanks for anyone’s help with this.
Larry L