Repeated , consistent under extrusion

[AndersK 29]

Can someone help me understand this please.

 

Have 4 failed prints where the problem occurs roughly after 5 mm build height.
 

Looks like it just doesnt feed the filament in the same rate as before.

I thought I had a grinding problem stopping the feed but last fail looked ok on the wire. (been changing retraction parameters and infill to reduce retractions)

Cura preview looks good too 

 

Nozzle isnt clogged, I can feed manually after a failed print and start a new print without doing anything, first 5 mm still works fine.

 

Edit :Its like its keeping the flow rate from ironing the planar surface while moving upwards... 

 

 

 

Edited April 15 by AndersK

[AndersK 29]

Might be on to something.

First failed prints was Cura 4

Now printing with Cura 3,6 and I'm past the problem area.