hmmm... this is a very complicated situation, and each situation is unique... but here's my observations from working with a child who had sensory issues.
You are correct that children with sensory issues act out and have behavioral problems. To a certain (and much milder) extent, i can understand why. I think i have some auditory sensory processing problems... and being in certain situations can make me insanely irritable. it becomes hard for me to focus, concentrate, and stay calm. i actually get irritated. I can see how a child who is young and not understanding what is going on can take that and act out on it.
last year i had a student (4 yrs old) who very obviously had sensory problems. They went undiagnosed and therefore untreated because his parents refused all evaluations. So things just got worse for this little boy. We did notice that he behaved the best when i was extra strict with him. there was a point where the only thing that would stop him in his tracks when he went on a rage (ex: trying to hit or attack a teacher) was raising my voice. At the same time, he was extremely dependent on me. Due to his aggressiveness, i took on most of the disciplining in the class. as time went by, he became too dependent on me. It was as if he genuinely needed the consistancy of having me with him, as well as the consistancy of the strict rules i laid out for him. To me it seems that when your world is chaotic and confusing (as it is for children with these conditions), you begin to rely on those who are consistant and strict to provide you with some continuity and even security.
I am not trained in this- this is based on my observations working with this child and a few others in the past. they need someone to establish order in their lives, which is what stepmom and strict teacher are doing. He is relying on that for security. If this is true, it makes sense that dad and losing you in his life is a stressor. And is it possible that dad may be a bit lax to compensate for both the past and the current work situation??
my best advice would be to encourage dad to follow the same rules/routines as stepmom when he is home. And please be sure to discuss this with his therapists. It sounds like this little boy has come very far, and with continued support he can go much further!
Dont leave his life is my answer, perhaps others who read your post may have better answers for you ,you say everything is okay with the child ,then thats what matters, amybe take a step back and let them get on with it.perhaps you are overreacting because you care,and they have him now, not easy maybe time to visit and thats it.
I guess my original enote was confusing. I raised the child for 3 years. His Dad & stepmom have had him for almost 1 year. While he listens to stepmom (and gets afffection from her) he does not listen to his Dad. Nor does he do well with one of the two teachers he has in school. He ignores the gentler teacher. He does not appear afraid of stepmom or teacher. My question was concerning possible abandonment issues as a result of my leaving his life. And since Dad is a firefighter and has odd hours that seems to compound the issue. If that is the problem. I understand that children with sensory issues do have behavior problems and wondered if anyone else had similiar problems with a child with this type of deficit or are we dealing with a little boy who feels abandoned and that is why he is acting out. Confusing I know, but this is not just a simple issue of blending a family. The child is just 4, so as far as he is concerned, everything is "ok".
Maybe I am confused but how old is your grandson is he 3 and a half , I am trying to figure it out in your post, it sounds as if there are issues withg his step mom you said he has a stern teacher (stepmom) and nice teacher (Dad)?? The fact he acts out when Dad is there is possibly telling Dad he is not happy, maybe Dad should ask him why ,there seems to be more issues to this and it is possible you are not fully seeing it.