MakerBot Print is our newest print-prepration software, which supports native CAD files and STL assemblies,
allows you to interact with all your printers via the Cloud, and many other exciting new features.
I'm not familiar with combing, so I'm newer to 3DP than you, but my Cura retraction settings for my Anycubic i3 Mega (full metal) are default and different than yours: 6mm, 40mm/s, 1.5mm. For what that's worth.
I expect you have checked for binding on the filament support and spool increasing tension on the filament.