There is this wierd bug I found where you can't change boots. For example, if I select the boots and move them to my inverntory, they move and instantly go back, it's the same if I swap it with another pair of boots. The only way to take them of if to equip another pair of boots using the hotbar (while the inventory is closed). Then you can take of the boots, it stops until you go to another dimension, or if you get off and get back on. 

Note: I use the pocket GUI setting.