New Spawner Item Not Working

Summary

New Spawner Item feature doesn't work. When I place it in the world, no mobs spawn.

• MM 5.8 Build 5300
• Crucible 2.2 Build 3953
• Minecraft 1.21.3

Steps to reproduce

Use provided Spawner File. Includes the default TestSpawner from the Wiki, and a modified one with looser light level requirements.

• Spawner Items: https://pastebin.com/qbcTMtAQ
• Server Log: https://pastebin.com/GDs2f3uV
• Screenshots: https://imgur.com/a/jA1Wfd0

thank you