Hempstead

You mean Cura 4.9? I just upgraded to Cura 4.9 from 4.8 too. I am having a similar problem. But on the 2nd extruder of my Ultimaker 3. No matter what I do, enabled Prime Blob or not... toggle the checkbox, power cycle, etc. etc. The 2nd extruder's Prime Blob was never generated with 4.9. It always went directly to the first adhesion layer of the 2nd extruder without the blob. The 1st extruder's prime blob worked for me though. I use breakaway on the 2nd extruder extensively -- pretty much every print except trivial prints. This caused the first few layers to be dry and incomplete thus rendering the whole support useless, thus pretty much all my prints failed. I had to revert back to 4.8.