IT’S fairly common knowledge that Google is a “Big Brother is watching” situation. They always know where you are. This is true even if you order them to stop. Turning off Location History should have stopped them from tracking you, however, this simply isn’t what happens.
Every time you open Google Maps, search something in your browser or acquire certain automatic weather updates they store time-stamped information without notifying you. This doesn’t just affect iPhone users, this affects Android and iPhone users.
If you value privacy then using Google Maps is a no-go and your best bet is to go to the Web and Activity setting and shutting that off. This will effectively stop Google from storing information. If you’re a Google Assistant user, however, this will adversely affect its effectiveness. It’s a double-edged sword, but you make the decision on your own.