The answer is in the above. Fantastical talks directly to the calendar services you are using, in contrast, Agenda uses the same system as the system Calendar app. This means that the events must show in the latter in order for them to appear in Agenda too. The way to do this is to configure your calendar services not only in Fantastical (that part you can keep as is) but also in the system preferences so things appear in both Apple’s calendar app and Agenda. Let me know if that helps.
I’ve spent rather a long time on calls with Apple support. They tried a series of diagnostics and potential solutions. TL:DR I erased the HD, reinstalled a fresh macOS and then reinstalled (only) my current application set.
all is now well - although I’m not sure what the cause was…
is it possible show connected calenders at all (like classic calendar view)?
If I want to plan some meeting I need to see 14 days before…
I can see only panel with upcoming events …
We don’t have a calendar view. The idea is to use your normal calendar app for most calendar functions. Our list is designed to make it easy to link to an event, but not to replace the calendar app.
Note that to see earlier events, you should be able to scroll upwards in the calendar view.