Turn off location services on your iPhone and then turn them back on. Make sure to be on the same WiFi so your Macbook can get the actual GPS coordinates from your Phone. Google maps on Chrome seems to be using a different method to find the location.
However, even by doing that it does work form me only when I first enter on a page. If I want to get the location again without refreshing the page in Safari, the permission is denied.
Ugly workarounds until, hopefully, in iOS 18.2 this will be solved...
Also, if my phone or mac has VPN tuned on it's goodbye to any location access :(
This based on my own discoveries in trying to figure this annoying issue while working on an app, so don't trust me 100% on it. I can't find the comment on this thread suggesting the same thing anymore.