@juched OT, but on a Blueprint thread (ZHA - Philips Hue Dimmer Switch (individual buttons with long presses)) for the Hue Dimmer, I am in a bit of a confusing situation you may have better insight on. The author has a zha_event for the dimmer that has long-release/hold functionality. My “new” Hue remote does, too. My three old ones do not and have a simpler structure (on, off_with_effect, step). The firmware shows 0x420045b6 on ALL four remotes – even though they have different zha_event structures. Device model numbers are all the same, too.
When you’ve upgraded your remotes recently, have you taken a look at the zha_event data for button presses? Trying to sort out if older firmware on these is actually more featureful or not.