I encourage you to keep talking to him make eye contact & just talk away. Read some good books , sing songs 😁 my daughter is the same age. I do this daily, I hope this helps 🙏🏾
I think that sometimes as they are learning a new skill, previous skills can go on hold for awhile. He could be gearing up for another milestone like rolling.
Yep very normal for 3 months. It’s really good that he’s laughing already even if it’s just sporadic at the moment.