Such a cute idea if it only worked

I have twins, so I bought two of these. They are not two yet but we set these up in the bathroom and let them use them whenever they want. To our surprise, they both have peed in them repeatedly, however, the music that is supposed to play and praise the child for peeing never worked. I thought at first maybe it wasn’t enough liquid but after multiple times I finally poured a cup of water right in it and nothing. This is both chairs. If you take the removal part out you can push the button by hand and it will play on both of them. The handle for the flush works as well and they really like that part. I’m just really disappointed that it doesn’t actually do anything when they use it. I’d say it was just a dud but when you have two it is hard to believe a third would be any different.