GPS Acciracu

My family can track each other via google maps.  Updates are sometimes infrequent and locations are frequently off by significant (quarter-mile, half-mile) amounts or moving hundreds of feet while asleep in a hotel.  Phones are Pixel 2 and daughter's almost-newest iPhone.  Freeways, big cities, places where there are lots of towers. Verizon and T-Mobile
Is it the phones or google or something completely different?
--
Cheers, Bev
    Bluetooth is especially problematic in San Francisco because it
    makes it nearly impossible to tell who is hearing voices and who
    is just talking on the phone, and in this city their numbers
    seem about equal.                                --Shaun Nichols