So in double F5 mode when you look at a block edge you can see the block outline which I think the problem is caused by the camera being slightly too into the block. Video may be low res because of size.
MC-242849
Block outline is visible in F5
Open
5
(Unassigned)
Confirmed
Platform
Low
Rendering
F5, block, block-outlines, camera, rendering
1.17.1, 1.18 Release Candidate 1, 1.18 Release Candidate 4, 1.18, 1.18.1, ..., 1.19.1, 1.19.4, 23w18a, 1.20.4, 24w04a
Retrieved
Can confirm in 1.18/1.18.1 pre 1