Summery:

Trial chambers do not immediately load when loading terrain.

How to reproduce:

Seed:193222952930161

Use creative mode but don't fly.

/tp 173 -21 186 (This position is inside the trial chamber)

Wait until terrain loads.

Observed result:

You will fall into lava below the trial chamber, then the trial chamber generate at your original place. (This doesn't always happen, so you may need to try multiple times)

Expected result:

The trial chamber will immediately generate when you teleport into it.