What driver are you using for these bulbs? "Generic Zigbee CT Bulb (dev)" is the recommended built-in driver, so if you're using another, I might switch to that one and see if it changes anything. (The "Advanced..." equivalent might work too, but they don't with everything.) Running the "Configure" command after you change drivers is a good idea, and for Zigbee devices like this it can't hurt to just run it once regardless if you're running into a problem like the one you describe.
That being said, as alluded to above, many Zigbee bulbs are known to be problems if mixed with non-bulb devices on the same network, as you might have with Hubitat. Using a Hue Bridge to keep them on their own network is one way to avoid this problem (a separate Hubitat would also work). There is a native integration that works well, as well as a couple of community options.
Many users report that newer Zigbee bulbs seem to work better (they are often Zigbee 3.0, but this alone is no guarantee of better behavior compared to the Zigbee Light Link profile used by earlier Hue and other bulbs--even if some people parrot this "fact" over and over
). I still like Hue myself, just with the Bridge, but there are other options, too! I see LIFX mentioned above, which now has a native integration. There are also some Z-Wave options, but I probably wouldn't fill my house with Z-Wave bulbs given how picky Z-Wave networks can be...