I've used different phones and uploading pictures to Google Photos was pressing a button and waiting for it to finish upload, in reasonable time.
I've recently got an S24 and not only it takes ages to upload, but anything else you're doing with the phone, and it stops uploading. If you shut off the screen, it stops uploading. If you're not constantly fiddling with the Google Photos app, it also stops uploading
I did press "Recent Apps" and selected "Keep open", and it's still not working. It's there some aggressive battery optimization setting I'm not aware of?
Why would you manually have to upload photos to Google? They back up automatically unless you specifically turned that feature off. Any time you take a photo, it ends up in your gallery and within seconds syncs to Google photos - no manual upload necessary. Oh, and upload speeds depends on your connection, not the phone set.
