Fallout shelter: Updated room produce less than before

Did you check your dweller stats? The higher the appropriate stat is, the faster the individuals in the room work. So take a water treatment plant. If your perception in the room is now lower than it was in your other room, the production time will be longer. You can fix early in the game by making your dweller wear outfits you collect to push the appropriate stat. Later, you can raise them using the training rooms.

On top of this, the happiness of your dwellers will all increase the amount of bonus resources you get.

I had the same problem when I first started. I started over like 3 times. Like what the answer says above matters also don't over do the rooms always make sure you have enough people to each room. When making babies do it one at a time. Don't make the rooms bigger unless you have enough people. Basically don't over do it. Patience is key.

Extensive research on room production.

Some width 2 rooms produce more then width 3.