Q: Home app location-based automation not working

I have a 4th Gen AppleTV and three Phillips Hue lights. I'm able to successfully create time-based automation, such as turning the lights on at 5:30pm and turning them off at 10:30pm, BUT if I try to set up location-based automations, such as "When I Arrive Home.." I keep getting the same error message over and over – I can tap on the "Try Again" and it will never resolve. This happens both when I'm away from home as well as at home on my home's wifi network.

The weird thing is, this setup seems to work when I do it from an iPad (mini 2nd gen and 9.7 Pro), but not from my iPhone 7. Any ideas what I should do here?