I think I have may sorted the issue (in part at least), I found the information in another post.
Part of the issue are the terms used in Bambu studio are a bit confusing and mixed. “retraction” hints that the action is having to do with retracting the filament a little to avoid stringing. “Z hop” is the action of raising the print head or lowering the plate a little to avoid dragging across the model.
So here is what I ended up doing:
In bambu studio => Others => G-Code Output: Turn off / Uncheck the option for [Reduce Infill Retraction]
Then in your Filament settings, go to: Flip the [advanced] switch to access the advanced settings, then go to [Setting Overrides]
turn ON: [Z hop when retracting] I set mine to [0.4 mm]
turn ON: [Travel Distance Threshold] I set the Threshold to [1 mm] but you may adjust as needed. I also turned ON [Z hop type] and set to Auto.
For reference:
This is the original post where they discuss the settings and why this effects z hop
Quote from original post
" Let’s start with the setting Z hop when retracting.
This is the key setting. It tells the printer to move the bed down (away from the nozzle) every time a retraction is made.
So, if we can force a retraction, we can force a Z hop, and get the nozzle clear of our parts.
Normally, any travel move over 1mm will trigger a retraction (see default Travel distance threshold). This would have prevented the scratching, but, it was overridden by another setting.
This other setting was of course Reduce infill retraction.
No retraction = no Z hop = scratches from nozzle"
I hope this helps.