The hype around the release first Nun was HUGE and so was the marketing push.
I don't think RT actually ever affected the business of spin off films from this series , it was mostly dependent on general interest and the fact that they just need to be slightly "scary/spooky" enough even if the script itself is severely lacking sometimes.
First Nun dropped the ball big time on the scares and the franchise havent reached its box office highs since then globally.
It is a pity because that film did significant business in India thanks to real hype and marketing blitz but they seem non existent of this one here.