Perhaps the campfires work ok on residential lots, and only bug out in other places?
I already tried moving the thing around a lot, repairing the game, and using both types available, but they still don't work most of the time (occasionally they do!)
However, if the barrel grill can be placed and then replaced in inventory, it might be a way around. Just not very believable, given making a fire out of rocks is easier than carrying a barrel across the jungle. But then when was the Sims realistic...?