Baby still cross eyed

My baby is almost 6 months old and his left eye still turns inwards sometimes. He quickly will turn it back straight, but I do notice it turning inwards when communicating with him and taking pictures. I mentioned it at his 4 month check up and his ped was not concerned yet, said we’d revisit at his 6 month check up. It’s gotten a lot better since the 4 month visit, but still happens.

Anyone else’s babies have it? Or any experience? I want to get it corrected before it gets worse! But I’m not sure if he just needs maybe need more time to strengthen it.