Slicer setting to stop this
Are you sure your stl is good? Maybe it’s not watertight?
If you upload it here someone can have a look at it.
I've cut the part of the STL that I'm having the problem with. I just want the flat surface on the top to be continuous, even under the extruded parts if that makes sense. I thought it would be the "Solid infill threshold area" that would fix this but that doesn't seem to work. Any help would be appreciated.
Oh and I did manage to sort it by slicing it in two parts (flat surface in one file, extruded top image in a seperate) and combining the gcode manually so I know its watertight. Just trying to see if there is an easier solution to this.