Put the summary of the bug you're having here

What I expected to happen was...:

previously the game has frozen before due to memory shortage, but it has regained itself nicely afterwards. So i expected the same to happen in 1.15

What actually happened was...:

The game caught up again, however the rendering of distant chucks (everything outside a 20 block radius) became glitchy in textures and rendering.

Steps to Reproduce:
1. Play the game, and cause a lag-spike or memory shortage.
2. wait for the game to catch up on processing
3. look around.