ujjayi Yep, thanks, tried that, and it opens Google Maps for a millisecond only to return the message "couldn't find location" every single time, and I've cross checked with other non-GOS Androids to see if it's a problem there also, and it's not. Been like that for the two years I've been running Graphene OS.
Well the good thing is does seem to redirecting to Google Maps correctly. The bad news is something else is going wrong. What happens if you get a location lock in Google Maps first, and then use the app?
Also, do you have Google Play Services installed? Apps that use the Google Maps API need Google Play Services installed, although the Google Maps app itself doesn't need it. Not sure if your app is using the API or not.