After phone upgrade to newer iphone - all photos are synced

Expected behaviour

After ihpone upgrade nextcloud is configured for photos and sync, only new photos from this date going forward is uploaded.

Actual behaviour

All pre-existing photos are synced causing a massive photo sync update - in my case 8000 photos.

Steps to reproduce

Replace phone with new iphone as upgrade.
Configure nextcloud with image sync
What seems to happen is the iphone starts to download all photos from icloud and resyncs them to nextcloud.

Reasoning or why should it be changed/implemented?

• Takes time and ressources to sync
  Changes made to images in nextcloud are owerwritten

If not exactly same configuration for file naming is choosen new images may get a new directory or image structure causing many dublets.

iOS version

14

App version

3.1.0.7

Server configuration

Operating system:
Linux debian configured in a docker container

Web server:
Apache

Database:
MariaDb

PHP version:
7.2

Nextcloud version: (see Nextcloud admin page)
20.05

No source file or test is named. Start by reproducing the iOS photo-sync flow after replacing a phone and configuring image sync, then inspect how existing iCloud photos are identified versus newly captured photos; done means pre-existing photos are not re-uploaded while new photos continue to sync without overwriting or duplicating files.