This is not an uncommon problem and there are a lot of threads on YT about this so you are not alone.
My advice to you would be to feed them BOTH pineapple~yes pineapple. Start with one piece each before meals like a treat. Make sure you pick up all poop so they do not have access to it for snacking purposes.
It will take a while t change the digestive enzymes in their intestines but it will work. After a few days if one piece does not seem to be enough then you can add a second piece. Pineapple will not upset their tummies and they will like it because it is sweet. There are LOTS of former poop eaters on YT but I promise you if you are diligent you can stop this gross little habit.
I can also guarantee your question will bring out all of the closet poop eaters with their questions.
One question~what food are you feeding? This could be part of your problem too. Foods that are very high in grains taste better then the ones with more protein. It's like they are making little warm loaves to snack on. I would like to add that this is not the only reason for a dog to eat poop such as momma's cleaning up after puppies and coming from puppymills but none the less it is a habit and that habit needs to be stopped and prevented.