This is a bug which i koticed recently on MCPE 1.16.0.58 (BETA). while i was playing and ready to enchant my pickaxe with 'fortune' enchantment, i noticed that the 'fortune' is not working. However, i tried to use combat-related enchantments such as smite, sharpness, power (bow), and even unbreaking seems to work just fine.

On the contrary, the farming-related enchantments like fortune, lure, looting, luck of the sea, etc. Doesn't work... At all. Please investigate this bug further so that we, MCPE beta testers can be satisfied of the outcome on the official release.