It's a tough one... Ella started solids at 4 months due to reflux, but the main issue with her was she couldn't keep enough calories down. She drank too much and threw up too much too, if that makes sense. So she would lose weight easily despite drinking a lot.
Solids can definitely make reflux act up more. You could back down to once a day between formula feeds and see if you notice a difference, otherwise, yes, I would stop. They don't "need" it at this age as far as nutrition, so if it's not helping...