It may be time to start solids
My pediatrician told me that if Avery started waking up at night hungry again or if she started asking to nurse more often around 5-6months old it would be time to start solids. He said that we had to make sure it wasn't just a growth spurt, but it's usually a good time to start exploring solids around this age anyway so it wasn't a big deal.
Start with filling, high calorie foods that are easy to digest. Avocado, Banana, or sweet potato that is mashed/pureed are great options. You can add a little formula to puree to thin it out or make the transition easier.