My world is lagging in certain area

I've experiencing weird lags in my world, it's single player and I have no idea why it's lagging, example : breaking block and it doesn't drop and more.   ( It's single player )

My phone has 4 + 2 gigs of ram and a good amount of extra storage for this map
and it's weird to be lagging in a single player world.

It looks like having tons of entity but I've killed all of them and nothing seems to work, and when i go to the nether, or leave the area in a distance. It seems to be fixed.

Watch until it's finished
This bug has been bothering me so long and doesn't seem to be fixed mojang

( https://www.youtube.com/watch?v=i75cY5i6A6c ) Watch until the end that's where the problem was.

( https://www.youtube.com/watch?v=r-Xr1VT7l3c ) At first, it wasn't lagging until I entered a area or chunk then the lags go insane, but there was no entity left since i killed it, still lag like insane, I've thought of my ram wasn't enough but nah

Please fix this bug