Not being able to feel restriction is usually pretty common till you get past the soft food stage. I remember thinking the surgery didn't work for me either, till I started eating regular food at 5 weeks. It was then I really felt the I'm full pain. I have since learned when to stop before it gets to that point. Liquids and soft phase were pretty easy for me. I still go back to it sometimes when my tummy is not feeling so good.
Just be careful that you don't eat more than you should. Especially this early out. You don't want to pop a staple or blow out your stomach. Extremely dangerous. Nerves have been cut too during your WLS and can contribute to why you aren't feeling that restriction. Give them time to heal.
At this point you want to go by how much your Dr recommends eating because you can't trust that not feeling restriction phase. I could always eat more than 2 TB of food but never allowed myself over 1/2 C early on. Also wait 30 minutes to an hour after eating to drink. If I don't, liquids won't stay down. I would concentrate right now more so on getting all your liquids in. Good luck!!
Here's what my nutritionist recommends:
5 weeks to 6 months: 600-800 calories, 65-100 g protein, less than 45 g carbs, less than 30 grams fat.
6 months to 12 months: 800-1000 calories, 65-100 g protein, less than 60 g carbs, less than 35 grams fat.
Over 12 months: 1000-1500 calories, 65-100 g protein, less than 75 g carbs, less than 30-60 grams fat.