Apple Maps storage problems
Why does Apple Maps take 20gigs of storage even when it’s deleted?
iPhone 16 Pro, iOS 26
Why does Apple Maps take 20gigs of storage even when it’s deleted?
iPhone 16 Pro, iOS 26
The pic belo may give some idea of what maybe happening.

Also, check if you have stored offline Maps on your device.
Offline maps in Apple Maps are stored on your device's local storage and are independent of the app itself. Reinstalling the app won't affect these downloaded maps.
Here's a breakdown of why:
However, it's always a good practice to double-check your downloaded maps after reinstalling any app. You can find them under the Offline Maps section within the Apple Maps app itself.
The pic belo may give some idea of what maybe happening.

Also, check if you have stored offline Maps on your device.
Offline maps in Apple Maps are stored on your device's local storage and are independent of the app itself. Reinstalling the app won't affect these downloaded maps.
Here's a breakdown of why:
However, it's always a good practice to double-check your downloaded maps after reinstalling any app. You can find them under the Offline Maps section within the Apple Maps app itself.
Apple Maps storage problems