After server update, loosing automatic images transfer on iphone client

Hi, after updating to 24.0.4, I loose “again” automatic image transfer from iphone clients.
Nextcloud server is running well, but when entering client on iPhones (3 different phones), images synchronization is lost and everything needs to start again, that means uploading a lot of images…(other 3K on 2 of them).
It’s not the first time it happens, and this time, it also required to log again from scratch, credentials were lost.
Did I do something wrong when updating ?
any idea will be welcome :slight_smile: