Gaps in several blocks, regardless of placement.

Several blocks, including Composters, Lanterns, Copper Lanterns, Soul Lanterns, Scaffolding, and Campfires, all have variably sized gaps in between the faces on the block. It does not matter where you place them, or how. They always have these gaps.

The gaps on campfires are particularly small, and may be overlapping rather than gaps.

Composters have gaps on the connecting point from the inner sides of the block to the top.

Scaffolding has gaps between every surface except for the outer corners on the legs.

Almost every type of lantern, excluding Soul Lanterns and Weathered Copper Lanterns, have very large and disruptive gaps between every surface.

The gaps on Soul Lanterns and Weathered Copper lanterns, while noticeably smaller, are still present.

I haven’t tested every block, but I imagine this isn’t an isolated problem.