Structure condition is broken with bastion remnants (random spawns)

Summary

The bastion remnant structure does not fire when combined with random spawns.

Steps to reproduce

1. Make new .yml in RandomSpawns folder with TestBox config in the debug log section
2. /mm reload

Current behavior

The custom mob is not spawned at all.

Intended correct behavior

The custom mob should spawn inside the bastion remnant.

Server log file

https://pastebin.com/eU6q8aWK

Debug log snippet

N/A, since there is no debug log for random spawns. Here is the entity spawn file, though:

TestMob:
  MobType: TestMob
  Worlds: world_nether
  Chance: 1
  Priority: 100
  Action: ADD
  Conditions:
  - structure{structure=minecraft:bastion_remnant} true

Proposed fixes

I don't know what the issue could be, but the documentation for the structure condition is also missing. Having documentation for that condition would help.