I like Philips Hue lights — they form a mostly reliable branch in my standalone home automation strategy. (In other words, I don’t use them with HomeKit, but only because I prefer isolated systems for reliability. Keep reading for why.)
Unfortunately, the Hue system has a serious flaw that can bite you in the ass when you’re traveling. Namely, the hub firmware and the control/scheduling app have to remain in sync, but you can’t update the hub remotely.
So, when you’re away from home, never allow your Hue app to update itself. Doing so could create a situation where your entire Hue system is disabled until you return home and update the hub, too.
Until Philips fixes this, live in fear of an automatic update, or simply don’t rely on Hue as a key part of your home automation system. (See first paragraph, above.)