Files in file app can not be referenced by KeePassium / dupes on file change

Expected behaviour

Keepassium (in my case) references a kdbx file in ios files app which is hosted on nextcloud. File could be changed by another client (KeePassXC on W10) an will be updated in nextcloud and files app for use in Keepassium.
There is similar issue in #1432 but it's not the same. See "Actual behaviour".

Actual behaviour

If a file was updated with KeePassXC, there are dupes on in files app for each save until I refresh. Dupes can be seen permanently in "Recent" tab. Seems to be a "new" file. Keepassium says (the former) "file not exists".
I can reproduce this with KeePassXC or KeePass-Client.
I tried with an text file without repro.
Also no repro by using another webdav integation for files app (e. g. Boxcryptor, FE FileExplorer).

Steps to reproduce

1. Reference KDBX-file in Keepassium
2. Change KDBX-file in KeePass or KeePassXC
3. Nextcloud Webinterface shows no dupes.
4. Nextcloud App shows no dupes.
5. Files app in iOS shows dupes.
6. KeePass shows "file no exists".

iOS version

14.3

App version

3.2.0.30

Server configuration

Operating system:
Ubuntu Server 20.04.2 LTS

Web server:
Apache 2.4.41

Database:
MySQL 8.0.22

PHP version:
PHP-FPM 2.7.4

Nextcloud version: (see Nextcloud admin page)
20.0.6

No source files, tests, or entry points are named. Start by reproducing the issue with an iOS Files reference to a KDBX file updated through Nextcloud, then trace the file-provider update and reference handling; done means updates no longer create duplicates or make KeePassium report that the file is missing.