Photos app often displays photo location as "Continental United States"

I've noticed in the Photos app that for many of my photos that I've taken with the phone camera, the location in the Photos view is indicated as just "Eastern United States". It seems that somehow the camera is no longer able to fully geo-tag some photos. On my iPad it says "Continental United States" for these.

However, some photos I've taken with the camera do display with the correct (more specific) geotag. I'm not sure why some have full geotags and some don't. Photos taken one day display a full geotag but those taken the next day just say "Eastern United States".

Any help would be appreciated.