Files with the .PDF extension are penalized if they are numbered

Files with the .PDF extension are penalized if they are numbered.
Hello? Can anyone help me understand why our owncloud is penalizing PDF files if any of them are numbered?

Example: the client uploaded a file called:
41240952273670000185550010000005961704369076.pdf

The APP application was automatically suspended for the client, penalizing them in 10 minutes.

Important note:
I would like some support
to check our server, and fix some functions.

I’m using it on a dedicated server with the following settings:

Intel(R) Xeon(R) CPU E3-1245 v5 @ 3.50GHz
Memori 32GB ram
10.6.19-MariaDB
PHP version 7.4

I have other problems as well, and I have been doing them, but they have no effect on the following fixes:

01 - Transactional file locking
02 - Integrity check
03 - Strict-Transport-Security HTTP header
04 - Memory cache not configured

I would like help to fix this!