I am just trying out the Free Trial of SD.

Here in southern Germany I am unable to see the standard Airspace C starting at FL100.
I can see C starting at FL130 in the alpine area, but not the standard C in the flatlands.

Same goes with airspace E. Visible when the lower limit is off-standard (like 1000ft)
but not when standard (2500 ft).

What am I doing wrong? Thanks a lot!

(and yes, I have well planned a route high enough - currently FL150)

That's interresting information. As I used "What's here" in order to have a look at what Airspace actually was there (between ground & upper level of SD). Seems I had it wrong (might be usefull to make that clearer in the documentation as well as it seems that I missed it). Might a solution not to have different behaviour between planning & in-flight ?
I think that for planning it would be usefull to know all airspaces that is at a certain point.
During flight I understand that it might only be usefull to have info on the airspace in the vincinity of where you are (I mean in hight).
This would solve the performance issue mentionned before.