Lost the nut for the filament feed out of the dryer. I tried other supposed M8 models but none worked. So I made my own. Printed in PETG at 0.1 mm layer height and 100% infill. Included the FreeCAD design file. The important adjustment is for the Hole thread feature - custom clearance. I set it to 0.200 but you might need more depending on the precision of your printer.  A clearance of 0.2 worked for PETG on my MK3s but PA (nylon) on my Core One needed 0.4, Alternatively, you could scale X and Y. I might leave Z scaling alone.