Today I opened SonarX3 and discovered that my Piano Roll view looks awkard.
I have no idea what caused this. Perhaps I changed it by accident without noticing the day earlier.
I've looked up the manual but I didn't find anything relating to this weird visualisation.
Do you know a way of fixing this?:)

It's just zoomed out to max. Zoom it in a little or choose Fit MIDI Content in the View menu.

Yea fit MIDI content did the trick. Thanks! :)
I'm suprised that I overlooked this tab...

I recommend binding Fit MIDI Content with Ctrl+F in the Piano Roll view, just like they are bound by default in the Track view. I almost always hit Ctrl+F after I double-click a MIDI clip to open the PRV.