Authorization of lecturers in series takes far too long

[dagraf]

Describe the bug
Situation: A lecturer does not yet have Read and Write permissions on a series in Opencast but is given course admin rights in ILIAS. Therefore, this lecturer can hit on "Actions" and then "Cut" on every video from this series. When he does so, he receives Read and Write permissions for this series in Opencast. As soon as this was achieved, the login form for Opencast appears and after the login the correct video is shown in the editor.

Issue: Since the update to ILIAS 8 time, it takes far to long (20-30 seconds) for the login window to appear.

Note: When a user allready has Read and Write permissions, everything works fast. Meaning, that after hitting on "Cut" the login form gets shown in 2-3 seconds.

To Reproduce
Steps to reproduce the behavior:

1. Have an ILIAS course, where your user has course admin rights and in this course have a series swhere your user does NOT have READ and WRITE permission
2. Open this series an hit on Actions > Cut on one of the videos
3. See that a new tab gets opened but it takes 20-30 seconds until the login form gets shown

Expected behavior
It should take far less time untill the login form gets shown.

Environment (please complete the following information):

• ILIAS version: v8.14
• Plugin version: v8.1.4
• Opencast version 15
• Browser: Firefox

Additional context
For authentification we use Shiboleth.

[dagraf]

Can someone try to reproduce this bug? That would be great. Thx!