Instamine not working

Instant mining occurs when your mining speed exceeds the hardness of a block by a factor of 30. The equation includes the base speed of the pickaxe, the squared value of your efficiency, and a multiplicative factor based upon your haste.

The Efficiency value is very important. Even with Haste 2, an unenchanted Diamond Pickaxe would be slower than an Efficiency 5 wooden pickaxe.

If you aren’t instant mining and your friends are, it’s likely because you are missing some level of efficiency.

Check out this resource to see what you should be able to instant mine for your given enchantments. It also shows the equations and gives some values for you to work with.

https://minecraft.gamepedia.com/Instant_mining

This resource will explain the concept more in-depth with more numbers.

https://minecraft.gamepedia.com/Breaking