You should leave your Wi-Fi on when away from home. If you don’t navigation apps will not work well, as most navigation is done using the location of known Wi-Fi networks. GPS only works outdoors with a clear view of the sky. Trees, tall buildings, and even heavy precipitation can block it. So leave Wi-Fi on and turn off VPN.
And something to think about→Don't use VPN - GITHUB
There are two legitimate purposes for using VPN:
- To allow access to a private network such as a school or business when you are not on site.
- To allow access outside of a country with a repressive government that has restricted Internet access. (This has suddenly become more important)
Any other use is risky, and can lead to problems. VPN disguises your location by making you appear to be somewhere else in the world. But you usually can’t control that “somewhere else”, and if it is in a location that an app isn’t approved for the app won’t work. Plus the fact that the provider of the VPN knows everything about you and your location, as well as what sites you access through the VPN. So you are totally dependent on the VPN provider’s honesty. As a start, if the VPN is free, DON’T USE IT. The provider has to make money somehow, and if you aren’t paying them then they are selling your private data to make money. But even those that charge can’t necessarily be trusted. For example, a few years ago Avast was caught selling user browsing data. They claim they have stopped doing so.
You don’t really need VPN when using public Wi-Fi, because all communications between your device and the servers it accesses are end-to-end encrypted.
If you want VPN for privacy about the sites you visit, that’s not a good choice as discussed; instead you should download and use the TOR browser.
With iOS 15.2 and later for iOS/iPadOS and MacOS Monterey 12.2 and later Apple now has iCloud+ Private Relay, which is not VPN, but provides a safer browsing environment than VPN, and it doesn't spy on you→About iCloud Private Relay - Apple Support