Mobile client not upload all photo

Good day!
I have Xiaomi RedmiNote 4 with Miui 8.0.4 (Global Version). After some time MIUI kills the process and nextcloud app too. After this point, the photo is not uploaded by the nextcloud app to server.
When I restart the application, new images are uploaded to the server, but no older. Sometimes, I have to manually synchronize the photo data, but it’s very tiring. I I forbade MIUI unload nextcloud applications, but sometimes an application still killed.

how to make an application to scan the photo directory to compare with what is on the server?
Nextcloud version 1.4.0.

Directory sync isn’t out just yet, so for the time being it’s a manual chore sorry.
@Andy this is likely related to what I’m seeing where the app gets terminated and doesn’t upload.

That depends on the Android base version MIUI is based on. Like @JasonBayton said (with the beta for pre Nougat) and for Android 7 with the 1.4.0 auto upload will take care of this to some extend with future version (likely 1.6 or 1.7) this will be extended and also rolled out to Android 5/6 devices. With these future version (yet to be implemented) we will also ofer a folder sync which would solve this issue independend from a specific Android version / ROM.
Unfortunately, for now the only way has been described by Jason already which is either a manual re-upload and/or a check of the uploads view and triggering a retry.