When placing a candle on the side of any block that is not on ground level, the candle will appear to float off the ground, rather than being visually attached to the block it is connected to.
Related issues
Attachments
Comments

[media]

The candle is supposed to float mid-air

Well, there is a bug that is currently being tracked in MC-203572 where candles act as full blocks, when they shouldn't. I believe that they should act more like decoration blocks and not have the properties of a full block, like saplings or flowers, for example.