Still Sync issues with mp-tube channels

Hi, I still have sync issues with The subscribed Peer Tube instances. for example I'm subscribed to !news@mp-tube.de with my instance: https://lemmy.rimkus.it/c/news@mp-tube.de

but the new Posts(Videos) are not autmatically synced. If I click on a Video on the original mp-tube site e.g.: https://mp-tube.de/w/4sH4HgqJXZeYAaKTZPaPY9 and enter that URL in the Search bar of my instance, it is successfully fetched from the site, and after that occurs in my subscribed channel.

Is it a known Issue with subscribed peertube channels? is there a solution or any way I can investigate deeper?

Thanks in advance :)