If you clone the 2nd coordinates are projected on the end position instead of the first one and they are half invisible and some totaly.
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that's not the issue, the issue is that in empty chunks 16x16x16 the blocks won't be rendered

no thats not true.

and that is MC-56917, in which this is a dupe of.

it is, see MC-56917

@FVbico: thats the totally invisible blocks

same issue as you are having, so it is a duplicate, the hitbox is there, just not the texture, same issue as MC-56917