the popcorn has to be removed. Popcorn is like a sponge it will soak up the moisture in the drywall compound and them fall from its own weight.
I do detest Popcorn because its almost impossible to paint unless you spray it.
To remove it lay down alot of sheeting and spray it with water and then just scrape if off.
Once off, then you must do any joint compound mending. then prime it. then do your new texturing, then prime it again and then paint it.
Sorry, about not being able to mudd over it.
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