Issue with File Attachments in Roundcube Webmail

Hello,

For the past 2 days, I have been experiencing an issue with attaching files larger than 1 MB through Roundcube Webmail.
I have not made any configuration changes recently, except for updating CWP.
Previously, the attachment limit was always set to allow files up to 75 MB.
What is interesting is that when I log into the control panel as root and access Roundcube from there, everything works correctly and large files can be uploaded without any problem.
However, when a client accesses webmail directly through something like mail.mydomain.com, it is not possible to attach files larger than 1 MB.

I am using:
AlmaLinux release 8.10
Roundcube Webmail 1.5.13

If anyone has experienced a similar issue or knows how to fix it, I would appreciate your help.

Best regards,