Not sure if this is related but recently have noticed that Dim Levels are not being set/sent between HomeKit and Hubitat. For example, I have an automation inside Apple Home to turn on some lights if a door opens at night but at only 10% dim. Those lights are a mix of HomeKit only ones and Hubitat ones. It used to work great but a couple of months ago the dimming portion stopped working. Now the Hubitat lights (all z-wave switches) will turn ON but the dim command is not received or registered, They come on to whatever the last dim level was. The HomeKit lights still work as expected. Also, when I look at the event logs I see the "ON" command coming across but I never see a command come across for dimming.
Perhaps something broke in Hubitat's HomeKit Integration due to one of the 18.x updates to iOS? Seems like that is about when I noticed the flakiness begin.
EDIT: A couple of other data points, I can manually change the brightness from HomeKit and it will get reflected through Hubitat and to the lights. It just doesn't work with any rules or scenes triggered from HomeKit.