@Flex_Westermaier A new update was released, try this as well in addition to the stuff in the above post. Who knows, you might get lucky.
One more thing: There are certainly cases where the ARC app starts showing “Poor connection” (even on home wifi) and then “Can’t connect to core” and “Core seen x days ago”. It seems that in most such cases this helps:
- Click the Reset button in the ARC app’s settings.
- Go to the ARC settings in the Roon app and click Reset
However, affected people usually seem to have “Ready” in the Roon ARC settings in the remote, not an error message like you. So maybe it’s not the same issue. (Maybe you are experiencing this issue as well, but it’s probably separate from your error)