Pretty much any supported Zigbee motions sensor should be about as fast and more reliable (the Xiaomi devices are not standard and are known to work well only with specific repeaters; even if they are close to the hub, you can't choose their route). The SmartThings motion sensor recommended above is great, but the Iris v2 (3326-L/3326-L2) motion sensor, long discontinued and only now getting hard to find, is a longtime favorite of many. The v3 (IL07_1) isn't bad either. The Osram/Lightify motion sensor is made by the same OEM as the Iris v2 and is also good. There are lots of other options, and you could also do Z-Wave if you wanted and open up even more. The only issue there is that in my experience, nearly all of these are slower than any Zigbee motion sensor I've used, which can be be annoying with (at least indoor) motion lighting automations.
In any case, yes, this is a Xiaomi thing. If you haven't read this thread about how to keep them happy on Hubitat, you should: Xiaomi & Aqara Devices - Pairing & Keeping them connected. If you want to not have to worry about this--something I'm slowly doing myself--then replacing them with standard devices should give fewer headaches. Most of them just cost more, so that's the tradeoff--and I think the main appeal of the Xiaomi devices in the first place. 
(PS - They've been rumored to be releasing Zigbee 3.0 devices soon for a while now, which if implented according to the standard should work with Hubitat and not be subject to these issues. But if they're intended to be marketed outside China or for use with other systems, they'll likely cost more.)
