Wow, that's almost 10% of missing plastic! 1.63 to 1.75mm is a big difference. Be sure to update your filament diameter on the "Other" tab of your FFF settings. Otherwise there will be far too little plastic coming out of the nozzle, which is probably why you're seeing those voids in the top surface.
The M2 settings included with Creator are calibrated using the MakerGear supplied filament, so if a different brand of plastic has significantly different properties, you might need to make some minor tweaks to account for it.