Bedrock Edition repost of MC-271167.
Previously, the tree in the "entrance_1" room (aka entrance room) of trial chambers represents a naturally grown oak tree. However, this was changed in one of the 1.21 preview versions.
Interestingly though, MC-271137 seems does not happen in Bedrock Edition.
Steps to Reproduce:
Find a trial chambers, and locate its "entrance_1" room.
Take a note at the appearance of the tree.
Now do the same thing in 1.20.80.
Compare them.
Observed Results:
The tree no longer represents a naturally grown oak tree.
Expected Results:
The tree would still represent a naturally grown oak tree.
Confirmed in Android