Recordings of live-streams: If the live-chat is activated it partly shown behind the thumbnail when opening the recording

[dagraf]

Describe the bug
If you have a published recording from a live-stream event where there were comments in the live-chat and you then open this recording, the shown thumbnail covers a part of the chat window (see first screenshot). When you then play the video, the video and chat window get correctly shown side by side

To Reproduce
Steps to reproduce the behavior:

1. Make a live-stream with the option "Chat for live events" activated and write some chat messages in the chat
2. Publish the recording
3. Open the recording by clicking on 'Play'
4. See the thumbnail hiding a part of the chat window

Expected behavior
When opening the recording, the thumbnail should NOT overlap the chat window.

Screenshots

Environment (please complete the following information):

• ILIAS version: v7.18 2023-02-01
• Plugin version: 5.1.0
• Opencast version: 12
• Browser: Firefox