The variant id's of the different types of falling blocks are different on worlds and realms, for example on realms a variant id of 0 is a blue candle, while on worlds it is an invalid variant and summons an invisible falling block that places absolutely nothing, another example is that on realms the variant id of -430992930 is invalid and places a blue candle but on worlds it spawns a falling sand block, another example is that on realms a variant id of -173245189 is invalid and spawns blue candle but on worlds it spawns a falling bedrock block, I know this because I made a mod that lets you summon falling blocks with specific variant id's, but it is really annoying that they are inconsistent because I have to make a separate event for every single block type and I would have to do it twice as much if this isn't fixed. 

Steps To Reproduce:  

1. Make an addon that lets you set the variant component of a falling block entity to either -430992930 or 1
2. Go on a world with the addon and set the variant component of a falling to -430992930, the falling block will become a falling sand block, then set it to 1 and it will become invisible
3. Go on a realm with the addon and set the variant component of a falling block to -430992930, the falling block will become a blue candle, then set it to one and it will become a blue candle but with a different block state. 

Observed Results: 

variant id -430992930 is different between realms and worlds, it is falling sand on worlds and invalid on realms. variant id 1 is different between realms and worlds, it is invalid on worlds and a blue candle on realms (different block states that the invalid ones). Invalid variants turn into different falling blocks on realms and worlds, it turns into an air block on worlds and a blue candle with the default block states on realms. 

Expected Results: 

The falling block variants should be the same on realms on worlds (including what block invalid variants turn into), either variant id -430992930 should be falling sand on both or invalid on both, and either variant id 1 should be a blue candle on both or invalid on both, and invalid variants should be either air on both or blue candles on both.