The Photos app of my phone sometimes stores the location where a photo was taken but only sometimes. (I have not yet figured out whether there is a pattern to this or not.) Is there a way to have all photos geotagged (with the default photo app)?
This problem usually occurs when you have a low or no GPS signal. If you take photos inside buildings, on high mountains, or rural areas, you might not have your photos geotagged.
You can try as much as you can to take photos when your GPS signal is strong enough (Maps app can show you a location accurate to at least 50m) or, if you remember the place on the map, you can manually geotag your photos, using this app: https://www.microsoft.com/en-us/store/p/geophoto/9wzdncrfj0f2