i was playing on 1.14.4 on mac and i came across a bug where instead of me being able to click an item in my inventory and click the desired location i had to click and hold to move the items.

if you right click and drag it will still. 

i thought this might be  mac issue so i switched my world to my PC, it was fine for a while but after a while the same issue arose.

also i cannot shift+click items but can use number keys to move items to hot-bar

i have tried restarting both Minecraft and the launcher but neither have resolved  the issue