I also started at 4 months and she’s now 6. She absolutely hates veggies now and want only sweat foods. She’ll close her mouth to veggies or gag but with sweet purées she’ll eat it. I’ve always been doing blw so I give her chicken etc and she eats it
But when I started with solids she played in it. It takes time.
Just sounds like he’s not ready which is normal for this age. Milk should be his main source of nutrition until 12 months so really milk should be offered if he’s not eating the puree. I’d say 7 months is when they are usually able to handle more texture. Have you spoken to the HV? 2-3 large pouches in one sitting isn’t really appropriate for the age so there may be something going on as to why he’s eating so much x
It sounds like he just isn’t ready. It’s completely normal. Most babies would start purees at 6 and move up to slightly lumpy at around 7 months. Don’t force it and let him take the lead. Also make sure he is having a minimum of 700ml milk per day as that is his main source of nutrients at this point