Filament insert problem

[TypQxQ]

I wanted to use my VZ-Hextrudort for my ERCF printhead but the filament is not entering the extruder smoothly. It has a flat surface instead of a chamfer where the filament enters and it gets stuck here. Also by hand it's hard to hit that hole. Is there anything I can do to ease it in?

[TypQxQ]

I made the insertion easier by using a short Capricorn tube with small inner diameter between the opening in the extruder and a PTFE tube retainer. I use 2.5mm id for my reverse bowden and Capricorn between extruder and hotend.