As of 1.20.31, Custom Biomes and Structures are completely broken. Any and All addons that require Custom Biomes do not work. Its not any addon specificly its all of them. It could be from and Website (9minecraft, Mcpedl, Forge, even one i created and imported to test it). Nothing works its completely broken, and its not just me. Ive seen post on reddit about this, comments on youtube about this. This has been a thing for a couple of months now and has made 90% of addons completely useless.