I’m going crazy trying to string this racket. I string the mains, skipping 7,9 but when I try to tie off at 8, string won’t fit. Have tried all the tricks but ended up popping both times as I was using everything from an awl to ice pick to oil etc...should I make grommet home larger before string job? Tried babolat rpm blast 16 and tnt 16. Frustrated!