(Step) Son Advice Please

Does any of you have advice for relationships with step children that may not like you? I can’t be sure but his mom hates me and she’s not very hush hush about it so either she’s influencing him or he’s made up his mind about me on his own. My parenting style is firm but loving. He has to clean up after himself most of the time (toys and minor things like that). I don’t believe in punishment beyond natural consequences, we don’t spank him or anything like that. He’s free to speak his feelings here. Before this social distancing we took him lots of places, had lots of fun and trips. He has lots of toys. I make sure his spaces are organized for him for a calmer environment. Don’t know what else to include about my parenting styles but anyway, he rarely ever engages in a conversation with me and when he doesn’t, I don’t try and force him to. To be honest he doesn’t hear or ignores half of what I say😂. He always wants to be locked in his room away from me and his brother. He’s 7 and a super smart kid. Knows everything about sea creatures and cars. Not sure what to do in a situation like this. I feel bad for my biological son because my 7 year old doesn’t like to interact with him too much and I feel bad for myself because I’ve been in my older sons life since he was 18 months old and I don’t understand what I’ve done to create this space between us. I love him, I just want to stay close to him but obviously don’t want to force him. Any advice?