If you summon a Falling Block with the BlockState Water or Lava, the Block goes invisible as it flies, then lands on the ground and turns into a normal Lava / Water source. When you take Flowing Water or Flowing lava as BlockState, it turns into sand.
Picture: At the left site of the screen, you can see that there is a shadow but no visual Waterblock
Related issues
duplicates
Attachments
Comments


Can you provide the command you used

Hello, this doesn't seem to be fixed in 1.16.4, when trying to summon a stationary water block in this fashion, the water block is still invisible unless provided with gravity in which case it'll re-appear when touching the ground:
/minecraft:summon armor_stand ~ ~ ~ {NoGravity:1b,Passengers:[{id:"minecraft:falling_block",BlockState:{Name:"minecraft:water",Properties:{level:"0"}},Time:1}]}
This appears to be a duplicate of MC-64634, which was later resolved as, "Works As Intended". This "issue" you are experiencing isn't actually an issue and works how the developers intended it to. See the parent ticket for further details.