Purge blobs in the middle of a print

Hi, I have a RRVC4 300 hybrid with the stock rapido UHF and diamondback 0.4 nozzle and an orbiter Filament Sensor (without macros only as a Sensor).
I am trying to print with creality high speed PLA.
In the middle of a print, the print head would stop, purge some material and unload then reload that continue printing.
This leaves purge blobs all over the print and I can't figure out what's going on.
I'm using a quite conservative 30mm/s flow rate (in the flow rate test I got to 45 mm no problem) 210 C nozzle temp and 60 C bed.
At first I thought it was due to the enclosure so I left about 2in of the front door open and it didn't help.
Does anyone else have this problem? Would appreciate all the help I can get, it's driving me nuts