Two things you could try.
The only time I’ve seen this issue is when I’ve first installed the switch and didn’t configure my preferred settings.
Try to adjust the max/min levels of the dimmers. Most of my don’t even start to turn on until about 30% and after about 80% I don’t even see it get any brighter. So adjusting these values also give it the impression of turning on/off faster as it doesn’t cycle through the irrelevant percentages.
The other thing that I saw mentioned was to change the “AC Power Type” and “Switch Type” settings, apply the change and then change it back to force it to get updated on the dimmer.
There is also a firmware update available that has some bug fixes too.
Hopefully one of these suggestions helps out.