After I rushed and failed rad roaches attacked and I had 2 people die but I revived one during the attack and one after the attack and the one after the attack I revived but my people still think the corpse is there and are continuing to be unhappy please help or fix thanks

Same issue here. I reported it to support.

This is super annoying. this happened in a fully leveled up 3-wide barracks for me and now I can't use it to produce offspring because it makes dwellers really unhappy to be in there with the corpse smell.

If anyone comes up with a solution, please post. I've tried letting a corpse room start on fire, but that didn't work. Next, I'm going to let someone die in there and see if reviving them removes the smell.

Well, killing someone in the room/reviving didn't work...

I have been investigating player happiness a lot today. I noticed that I had one Dweller at 10%-20% and stayed there consistantly. There were no dead people. His special stat made him best for Water but when I moved him to the cafeteria his happiness went up to 75% and has stayed there. Move the unhappy Dweller to other production rooms until his happiness goes up. You may want to leave him there and train his special if that's where the Dweller prefers to work. I recognize it could be a bug as well but that's what I have seen for my game today.