Hi, I'm developing a mod for minecraft, the main goal of which is to optimize the rendering of a large number of players, everything works tolerably well, but there are such bugs in the studio. Don't know what this might be related to?

it seems to me very strongly that glClearColor is forgotten somewhere

Bug screenshot

briefly about my modification.
The mod is being implemented in PlayerEntityRenderer.render
Replacing the code with mine
My code binds its shader, its Indexbuffer and VAO
then draws objects

UPD1: (2023.04.29)

Today I found a supposed problem place. The problem appears immediately after calling <init> in the IndexBuffer class of my engine. The constructor code is attached below.

Bug fixed by this code