Here's a photo of a print I stopped after the first couple of layers. You can see the 'blobs' deposited when a new layer starts - the extruder gives a short forward burst.
I have tried printing files done some weeks ago and they are fine. It is only the new ones I produce that are showing this.
The 'Extra Restart Distance' on the Extruder tab was set to 5.0. Have never even considered this parameter before, so no idea how that got changed.
All a bit odd......