i feed my girl solid food when she wake up from her nap around 2/3 and 5/6. you can follow the formula chart if he drink lesser just make the amount he drink or you can check with doc how many ml he should drink.
1x solid 1x snack 180ml 3 hourly during the day and nurse at night.
I feed milk before and after naps and sleep. Solids after milk.
4x180ml milk and 2 solid every 3hrs