Profiler Stage OS Update impossible via Rig Manager

My Profiler Stage is connected to a MacBook. Rig Manager works well in this configuration. But one problem: I can't update the Profiler from the Rig Manager. I checked with all different settings under preferences (automatically check on/off, included beta on/off) but nothing happened automatically and the manually check shows "software is up to date" - but it is not up to date.

My Profiler OS is 8.0.2 but the update 8.0.3 is announced (8.0.5 as beta). The Rig Manager is up to date (3.0.145).

I have also tried the update from a Rig Manager installation on an iMac but also without success. The difference is, that on the MacBook the message "software is up to date" is shown but on the iMac nothing happens. The command "Check for Software Updates" remains grey but no message is shown at all.

MacBook and iMac are connected to the internet, of course and both are able to load files from Rig Exchange. It's only the update that doesn't work. Because of that reason I've made the last update to 8.0.2 (in November) via USB stick but I would prefer to use the Rig Manager for that part of administration. How can I keep it working?

PROBLEM PARTLY SOLVED

I made it working on the iMac. I unchecked the Rig Exchange Option and checked in again, then the update process from the Rig Manager was working. But this solution doesn't fix it on the MacBook.