I’ve mounted the Longmill Mk2 adapter plate onto my Longmill Mk2.5. But when I go to mount the 80 mm spindle mount onto the CNCPWN adapter the M6x80 screws provided with the mount cannot thread into the threaded holes in the adapter. They seems to be too big, but an M5 is too small. The bolts immediately bind and cannot be advanced. There is noticeable scuffing on the bolt and in the threaded hole, so it doesn’t look like it fits well. Any advice?