In Minecraft 1.14.3, the grindstone does not remove the curse of vanishing/binding enchantments however they are removed when two tools/armor pieces containing those particular enchants are combined in the crafting table.
MC-157107
Crafting Table Curse of Vanishing
Resolved
Duplicate
0
The part where the grindstone "does not remove the curse of vanishing/binding enchantments" is intentional, only non-curse enchantments will be removed. This is listed in: https://www.minecraft.net/en-us/article/minecraft-snapshot-18w48b