On Java Edition, you can place a light block on another light block while sneaking, However, it doesn't on Bedrock Edition. This also makes map-making a little harder.
Step to Reproduce
1. Place a light block.
2. Try place another on top or the side of it while sneaking.
It should be placed on top and on the side of another light block.
It doesn't, instead, it resets the light level back to 0.