I can't get S3D to extrude reliably (I get a "string of perls"), on my Robo3DR1, unless I set the extrusion multiplier to +1.35. I've seen other posts where users have their multiplier set below 1. I have no issue with extrusion with the supplied Mattercontrol software, where the multiplier is set to 1.0. Makes me think that the filament speed must be greater in Mattercontrol. Is this normal?