The bug

Sweet berry bushes / sweet berries do not grow if they have a (solid?) block above them.

To reproduce

1. Plant a sweet berry bush
2. Place a solid block above
3. Run /gamerule randomTickSpeed 10000 or just wait a while
   → The bush will not grow

Code analysis

TriWonder81 - The following is based on 1.17 Release Candidate 1 yarn mappings.
This is caused by the following statement of net.minecraft.block.SweetBerryBushBlock in which the light level of the position directly above the block is checked. This is why only solid blocks stop the growth, as transparent blocks allow light through

if (i < 3 && random.nextInt(5) == 0 && world.getBaseLightLevel(pos.up(), 0) >= 9) {
            world.setBlockState(pos, (BlockState)state.with(AGE, i + 1), Block.NOTIFY_LISTENERS);
        }