Help with printing setting

Hi, I am new to 3d printing, I have an Ender 3 S1 printer and use Cura as a slicer.I had great results when printing in the beginning. However, i noticed on my last print that the nozzle id dragging on the print when moving. on close inspection, i noticed that on some lines it appears the nozzle is over extruding causing surface area to be bumpy. I noticed this only happens on the outer walls and not on the infill area as you can see on the attached photos. I checked and the carriage motion is smooth and continues (no stops or pauses) discounting the issue of power failure back up.I have discounted moisture in the filament as the issue appears to happen on the walls and not the infill.I had done some research and had carried out some calibration to make sure the nozzle is not over extruding. I made a mark on the filament at 100mm from the top of the carriage, extruded 100mm and it was on point. I have reset the Cura print settings to default and did a test print and the issue is still happening.I did not clean the nozzle nor did i check the feed gear as both are new and look to be in good working order.Can anyone give me some pointers/help on how i may resolve this issue. Thanks all.