I can get the same behaviour on Chrome app on IOS 15-2-1 and the app. Both hang after shifting the time bar
iPhone app - when scrolling forward in time on the default page, the app hangs completely. The point at which it hangs is apparently random but always - sometimes scrolling forward a day or two, sometimes, I can scroll forward a week and it hangs when scrolling back. I have tried uninstalling and re-installing the app but the result is the same. The hang always seems to occur while actually scrolling, not after a scrolling action. The hang appears "terminal" in that it doesn't unhang after a period of time BUT there is a whirly wheel spinning to the left of the "time" central icon as if it is struggling to acquire data. The behaviour is the same on wifi or 4g. Eventually the spinning wheel also hangs. Closing and re-starting the app resolves the issue. Otherwise the app is totally unresponsive.Not experiencing any other connectivity problems!