Mending is not working - XP is not applying to armour or tools

Coastal Village Seed: -1813740965 (created v. 1.5.0 Beta) Survival Mode; Normal Difficulty; Infinite World Type.

Mending is not working - XP is not applying to armour or tools. I noticed my armour and tools with mending enchanment were wearing out. I had to repair them on an anvil. I have a drowned farm which generates a lot of XP. Also, fishing and mining Redstone, Coal, Diamonds, and Emeralds are producing XP which is not appled to the aforementioned items.