This is about the interpolation feature.
Expected Behavior
When typing in the phenomena box I'd expect the website to tell me, which phenomena are available instead of being forced to guess.

Actual Behavior
The user can only guess, what phenomena are actually available.
E.g. a German speaking user might search for "Feinstaub" which returns neither an interpolation nor an error message.

The input "Feinstaub" doesn't work but the user get's no feedback.
The user has to already know the exact name of the phenomena (e.g. "PM10") they'd like to use for interpolation but the user has no other chance than to guess.
In some cases, there is an error message, but a very general one which is not helpful to the user:

The input "PM" returns an unspecific error message.
Environment
- OS: Windows
- Browser & Version: Chrome 87