I have a few Xiaomi buttons ("smart switches"), bouth the round (original?) and square-ish (Aqara? or is it the other way around) versions, and I've tried them both with a couple different ST DTHs I ported. Both pair, but neither really works in terms of registering the button press as an event beyond a checkin.
I also have a few Xiaomi motion sensors and door sensors. Both have paired and worked correctly for me for a while, but within a day or so, they "fall off"--- a problem some ST users are probably familiar with. I'm trying a different DTH now and some ST tricks (leaving them near the hub with the hub in pairing mode for a while), but I'm not sure if that will work on Hubitat. I'm not sure how Hubitat implements ZHA, but maybe it's related to the problem discovered by some users of the Bellows library that Home Assistant uses: https://github.com/rcloran/bellows/issues/43
These aren't standard ZHA, so I'd have no reason to expect them to work, except they're close enough that many ZHA hubs can apparently be tricked into using them, and I have a few, so I'm hoping it can work. But for now, I'd put these---and really probably most Xiaomi ZigBee devices---on a "not really but kind of maybe" compatibility list.
EDIT: In case you are reading this thread much later than my original post, Hubitat works pretty well with these now, probably similar to ST, after an early hub firmware update. But there are problems with repeaters, so using ones know to work well with Xiaomi devices (or none and keeping them all in good range of your hub) would be my recommendation, Other threads have more information on this,