@netschmiede24 @wfandrea @mainwebp
Sorry for the late reply. In the meantime i think the issue fixed itself:
As mentioned I installed the Tagembed plugin for WordPress and created the LinkedIn feed from scratch there. I also activated the auto moderation function and set a simple rule to filter by handle (the handle of my client feed in this case) and the condition “public”. Since then it is updating regularly with a delay of not more than a day. Occasionaly i have to manually moderate certain posts that slipped through the auto moderation and were deactivated previously. But that’s not happening very often.
I hope this helps anyone with the same issue.