Same issue with me. Seems to be if you are still using Mac OS Monterey 12.7.4 with Safari 7.4.1 then Linkedin videos do not show a picture, only sound
I spent 2 weeks trying to work with Linkedin support, got past first desk and sent screen recordings of the issue. The last reply is shown below - basically 'we don't know'. I've moved over to Duck Duck Go which works fine - no point wasting any more time trying to make this work
Linkedin final reply from tech support...
Thanks for your response.
I apologize for any inconvenience this may have caused. We have confirmed the issue and have escalated it to our Technical Escalations and Engineering teams for investigation. At this time, there's no estimate as to how long it might take to resolve. We'll do our best to provide progress updates as they become available. For near real-time information about the availability of LinkedIn's products and services, please visit: http://www.linkedin-status.com
In the meantime, I'll gladly help if you have any other questions.
Regards,
Riya