Sculk vein can grow and be placed onto light blocks, where light blocks are supposed to be an invisible block that no plant can grow or be placed on.

Step to Reproduce
1. Place down a light block.
2. Put Sculk catalyst next to it.
3. Kill few mobs next to the sculk catalyst to grow the sculk veins.

               OR

1. Place down a light block.
2. Put Sculk vein next to it.
3. With the Sculk vein in hand, click the Sculk vein placed in step 2.

Expected Result
Sculk vein cannot grow or be placed onto light blocks.

Observed Result
Sculk vein can grow onto light blocks, which makes the Sculk vein as if it was floating. Or will be placed on the light block next to the Sculk vein, not replacing the light block.