I have replicated this issue using version 1.18.31 on 05/22/22 on PC and PS5 and the issue exists!
Problem: Guardians do NOT spawn within soul sand bubble elevators.
Why it's a problem: This is an unfortunate issue because Guardian Farms are a rare and challenging achievement! Few players will try in the first place, and even fewer will now be successful with the resurgence of this bug.
Edit 05/23/22: Additional 5 hours of observation spawned a single Guardian. This may show that Guardian spawning within bubble columns happens either never, or with extreme rarity once the soul sand bubble elevator is built.
AlecWiener
I have replicated this issue using version 1.18.31 on 05/22/22 on PC and PS5 and the issue exists!
Problem: Guardians do NOT spawn within soul sand bubble elevators.
Why it's a problem: This is an unfortunate issue because Guardian Farms are a rare and challenging achievement! Few players will try in the first place, and even fewer will now be successful with the resurgence of this bug.
Edit 05/23/22: Additional 5 hours of observation spawned a single Guardian. This may show that Guardian spawning within bubble columns happens either never, or with extreme rarity once the soul sand bubble elevator is built.