I have taken pictures before and they show up in the photo gallery. The other day, I was taking a picture and the phone clicked 30 times in rapid succession giving me 30 pictures of the same thing. I deleted those, but the phone isn’t saving any pictures that I have taken in the last couple of days.
I don’t have a G4 to test, but recently discovered that after a factory reset all my pictures on the Moto X Pure ‘appeared to be gone’ … even though I had insured they were backed up to Google before the factory reset.
I found them by utilizing the ‘Photos’ app that is also on my phone along with the ‘Gallery’ (which remains empty)
I’m not an expert on photos but I have found that indeed the Google Photos app is synced to your photos while the Gallery app is simply tied to your photos stored on your phone. That’s something to watch for if you use the Gallery app versus the Photos app since you’ll delete photos using Gallery; however, you haven’t deleted them from Google Photos.