When going to the nether, a lot of lava is generated floating in mid-air.
 
What I expected to happen was...:
I don't expect to see an entire lava sea floating midair.
 
What actually happened was...:
I see a lot of lava floating in midair in the nether.
 
Steps to Reproduce:
1. Create a new world with seed -8605642373952595818
2. Go to position: /execute in the_nether run teleport @s -403 22 459 -10 0
3. Look at the floating lava
 
Flying around you'll see that this isn't uncommon, and there is a lot of floating lava.
/execute in the_nether run teleport @s -435 29 450 160 0
/execute in the_nether run teleport @s -608 29 337 150 0