Hi there! This might be part of your issue.
Crate pickaxes like "Insane Explosive Pickaxe" (and all pickaxes that go beyond their p0 enchantment limit) don't count for your prestige level.
For example, if you're trying to 1st prestige an "Insane Explosive Pickaxe" with an Explosion level of 3326, the server's pick prestige system will only count the first 1250 levels of Explosive. The other 2076 levels of Explosive will not be considered for a prestige.
This is, to the best of my knowledge, not a bug.
If your problem was not what I mentioned above, and was not solved by /enchanttoggle, all I can suggest is that you make a bug report.
Best of luck!