Slabs are acting like full blocks and make lighting glitches. Slabs will break the grass below although I don know if this is a new feature or not. But there is an issue where the upper half of adjacent blocks gets dark as though there was a full block next to it. the top of the adjacent blocks stay normal.
Also slabs will get darker in certain areas when they are floating next to full blocks.
Stairs blocks are also affected.
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However, this issue is a Duplicate of MC-123117.
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