Ever since the nether update, bubble columns will not generate. I just went to finish up an elevator I was building in a world that existed prior to the update, and the bubble column will no longer form.
The exact setup in the attached screenshot worked fine previously.
Thank you for your report!
We're actually already tracking this issue at MCPE-85448, so I will resolve and link this ticket as a duplicate.
If you would like to add a vote and any extra information to the main ticket it would be appreciated.
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