If someone has not visit his parent’s kever within 10 years is there a minhag not to go anymore?
There are seforim (Taamei Haminhagim 1070 from the Divrei Chaim) that bring such a minhag. The reason for it is not that it is forbidden to go, but rather because if the child didn’t go to the parent for ten years, most probably the parent will be upset with them and won’t help them bring their tefilos to shomayim, therefore he shouldn’t go.
This minhag has a number of limitations. It only applies to a parent, not to kivrei tzaddikim. It only applies if the reason the child didn’t go was because of negligence, but not if he couldn’t go for whatever reason. It doesn’t apply to married women, since they are busy with their husbands and children.
Gesher Hachaim 29-16, Dudaei Hasadeh 38, Even Yackov (Valdenberg) 44-4.