Block/Mob glitch at specific chunk or time during playtime

When I do some action in world (created in previous versions of the game (1.8 and 1.14)) a bug appears, or more at the same time.

1. When a block is mined in survival mode and is drops as an item, the item cannot be picked up at all

2. When I drop an item from the inventory the item replays the drop animation, the same can happen to the items affected by bug 1

3. Sometimes when the bug 1 is happening to the sand type blocks, the said blocks are repeating the animation of falling before they were mined (mined the block beneath the glitched block, block falls, mine it and it glitches

4. Sometimes mobs stuck in one place and cannot be touched (can be walked through)

5. When I use command "clone" the blocks I cloned to  a different position are not appearing, or are invisible and the only way to make them appear is to place blocks so the cloned blocks at that place would replace the manually placed block there

6. When I "Save ad Quit to Title" a world and open a different one in the same game, the loading gets stuck (the same happens when I try to open the world I closed seconds ago) 

All bugs vanish after closing/restarting the game, and are happening is one or multiple chunks, not a whole world, because the bugs are happening at one place at a time.

Note: this bug happens in worlds created in old versions of the game and in worlds created in 1.14 and 1.14.1, and happened to me only in 1.14 and after