You could fix this with a custom DTH. I wrote this to simulate on/off fade dimming for GE ZigBee switches. I would guess this should work for you. Available from my jhamstead/jhamstead GitHub as well (updated there).
As a note, when using the ZigBee attribute to turn on at a specific level, this changes the off behavior. When turning a switch off it will report the dimmer level as 0% but will turn on to the last level.