Weird crossfade pointer? Crossfades cannot be moved (properly)? Crossfades deleted automatically?

I realised, that this pointer
image
usually shows up, when having 2 events, which are not crossfaded with each other, to move the edge of both around at the same time. So the main issue here is, that Cubase sees a crossfade with a length below 11 ms, as “no crossfade” and treats it like it.