Yesterday I received an email from Microsoft with a workaround of issue (bug) I mentioned earlier , see here. Indeed the error is a bug in Beta 1 and will be fixed in Beta 2. For a workaround follow the following instructions :
Workaround: Customers in the affected timezones should set the times on their machine to either GMT or to timezones lagging GMT. They should change the clock time prior to opening the Admin Console or open a new Admin Console window, where the changes will have taken effect.
After opening the Admin Console with the clock set to GMT (or GMT lagging) and refreshing the Group Hub page (or running a specific query), users can reset the clock on their machine back to their GMT+ time. The Group Hub page will continue to work since certain cached time values are used.
The workaround steps have to be followed for each new Admin Console window which is opened.