Why does it feel like my 4 year old is harder on me then any other person in the house hold?

I (F28) am a first time mom. I do my best as a parent, like most people try to do. I don’t do aggressive parenting, but with a profession in caregiving I’m pretty good with setting strong boundaries, expectations, and punishment/rewarding when necessary. I’m also a very affectionate mom, hugs, kisses, words of encouragement, really anything to encourage my son in anything he does from his art to little drumming he does. Lately though it feels like no matter how much love I put in, my son can be very aggressive with me. Just talking to him he’s very snarky with me, doesn’t listen to me, pushes my boundaries emotionally and physically, just over all a bit of a bully. Now being a 4 year old and being mean is something that is to be expected with any kid his age and with the emotional competence that he has. It just seems like every other person who lives our house (Dad, Grandma, Grandpa) get a completely different side of my son. To them he is very peaceful, tends to just chill out, very rarely starts issues on their time. He talks sweetly to them and doesn’t scream or demand them to do things for them. I don’t get stories of him throwing toys, slamming doors, or hitting them (sometimes with dad but not as frequently as myself)

I will say he’s not like this all the time with me, and we definitely do have great days together. tonight though we had an incident where I set clear boundaries with him earlier in the day for getting trouble at preschool for being aggressive with his teacher. 1 strike and it’s early to bed. Simple as that. Night was ok, a few mean comments and a few snarky “what’s?” But otherwise fine. We were sitting on the couch and we were going to watch something together while we waited for dinner to finish up and out of nowhere he just leans over and hits me over the head with his fist. So I told him to go take a time out in his room and then came the screaming and running, slamming doors, trying to slam doors on me, the whole works. It was an absolute mess. After I made him an early dinner and made good on my word for an early bedtime I went into my room and kind of sat there and thought which lead me here. I guess my question isn’t only why does it feel like my 4 year old it harder on me, but also how do I know if I’m the problem and how to I change myself as a parent so this sort of behavior isn’t an issue anymore?