I know you have had previous reports of this back in 1.13 but it is still not fixed even though it says resolved. When you mine stone with silk touch it gives you stone and when you smelt cobblestone it gives you stone that does not stack with the mined stone. Also, villagers do not take the smelted stone. I hope I didn't annoy you with another one of these but it is a very aggravating bug in the game at the moment.