Use BM gems, it's +2 and it has a higher rate than gem+1 I can never get pass +7 when I use a +1 gem. Easily get pass +7 when I use a +2 gem
Are you trying to get to +10? Or are you trying to get past +10? You can't get past +10, and if it's not letting you get past +9, it must be glitched or something.