Support request, someone with NextCloud experience help me decrypt my files

Good afternoon!
Support request, we can pay for the service

Can someone with NextCloud experience help me decrypt my files on my NextCloud server? I have the encryption keys and the necessary access credentials. Another solution we would like to see is to have NextCloud take all the folders present on the server and index them again and join them to the ones recovered with the backup.

Server details:
cPanel Version 88.0 (build 11)
Apache Version 2.4.43
PHP Version 7.4
MySQL Version 5.7.30
Architecture x86_64
Operating System linux
Path to Sendmail /usr/sbin/sendmail
Path to Perl /usr/bin/perl
Perl Version 5.16.3
Kernel Version 3.10.0-1062.18.1.el7.x86_64

Chronology of events:

Event 1: I organized all the information on the Nextcloud server, everything worked fine until July 1st.

Event 2: shortly after, I started some updates on the server to optimize Imagick, and I received a call that the Nextcloud server gave an error 500, and my colleagues could not access the Nextcloud data.

Event 3: I proceeded to recover the last available Nextcloud backup dated June 29, but not all the subsequent jobs were on the backup. Once the backup is restored, the data on all the computers where it was stored is replaced.

FAILURE: Nextcloud does NOT show all the files that are on the server, only the data recovered from the backup is shown, and the last jobs that are needed remain on the server, but are not taken into account by Nextcloud.

NOTE: If the files are downloaded, they are encrypted, and some of these two solutions would be needed.