Lazy Chunk Loading and Performance on Preview, not in 1.18.33

This is quite self-explanatory. See the images below first.

The world chunks of Infinite Worlds fail to load on the Preview, but not in 1.18.33. 

There is also noticeable performance drop in the Preview compared with 1.18.33.

However, there are no issues for Superflat worlds.

The Device is iPad Pro 2018 12.9-inch.