Users are not able to complete Quizes

Hi everyone,
I’ve been working with Frappe LMS for some months and everything was working perfectly.
This last weekend I decided to update the platform by performing a docker pull of the latest stable images and a bench migrate of my site. Everything seemed to be working well. However, right now, lots of our users are not able to completed their Quizes.
They are getting a 403 error when trying to complete them, with the following error:

XHRPOST
https://<mywebpage>/api/method/lms.lms.doctype.lms_quiz.lms_quiz.quiz_summary
[HTTP/1.1 403 FORBIDDEN 331ms]

{"exc_type":"PermissionError","_server_messages":"[\"{\\\"message\\\": \\\"El usuario <strong>xxxxx@gmail.com</strong> no tiene acceso a doctype a trav\\\\u00e9s del permiso de rol para el documento <strong>Inscripci\\\\u00f3n LMS</strong>\\\", \\\"title\\\": \\\"Mensaje\\\"}\"]","_error_message":"Sin permiso para Inscripci\u00f3n LMS"}

In our platform, every student has the exact same role, the default “LMS Student” one, and that’s also the only role they have.
With that role, some users are able to complete the Quizes while most aren’t able to do so, they keep getting that 403 error.
This used to work perfectly with version 4.20.0, but it isn’t working now for some reason.
Also, there are no error logs on the server side for some reason.

This has never happened to us. Is this a known bug? Is there any way I could fix it?

Best regards,
Javier