Walls are not rendered correctly from certain angles, certain positions, certain states

Can you reproduce this while not in a debug world? This may be intentional texture culling.

@@unknown It can be easily reproduced with a debug stick. This can be useful for decoration.

It's to reduce lag because normaly those sides are not possible to see

This seems to be described in MC-182844, which has been resolved as "Won't Fix"
Fixing this could result in a performance loss from rendering unnecessary faces.