Problem with Insteon dimmer switches from ElkM1 controls.

[GMcBride01]

I have an ElkM1 with ISY994 controlling several Insteon 2477D dimmers. It has all been working great for years. Recently, when an ON command is sent from an Elk programmed command or even through the ElkToGo software, the dimmer ramps to full ON as expected, but then immediately ramps down to 54%.
They all work normally from the ISY control panel.