The update mode is set every 1 minute, but sometimes it updates less often. Why?

In order to update GPS every 1 minute, the phone must be in the zone of good GPS reception (in the open space). Also, the phone should have a stable Internet signal.
Unfortunately, in the conditions of the cities, these signals are often unstable. Therefore, if the app is set to the update mode every 1 minute, the actual update occurs every 1-3-5 minutes. Sometimes less often.