I simply desactivate localisation in the phone settings by default. If you aditional use an VPN even better

There is an option in the developer options to enable a fake location app.

https://github.com/lilstiffy/MockGps

Ideally you would want to remove your carrier sim. your carrier will know you are in a different country (roaming), and use a good VPN

I use mullvad VPN and that spoofs my GPS and location.

I use Lineage on my current phone with no google apps and dont use a fake location app.

If you are using a default, we love google phone, I am not sure if disabling the gps and location stops google and its apps from having access to your location data.

I dont trust them to honour the pressing of a button to disable anything, when location and advertising is so important to them, and their other surveillance friends

Fake Traveler is another GPS spoofer that was recommended online, since you say MockGPS didn’t work consistently for you.

There's this one from a quick search on IzzyOnDroid.

Disclaimer: I haven't tested it.

Why spoof your location instead of just denying location permissions?