Why am I ignored at work? Is it because I’m too nice? Or autistic?

I mean I am doing my best to work with the children and being more careful but I feel like I’m not appreciated and ignored. Like I do like my job so far, but when I make suggestions I’m often ignored or someone just nodded their heads but the others is listened. I think the other staff isn’t doing much to help at all. Is this the three of us that are doing most of the work but I think she’s doing a lot better since someone talk to her about it. She seems quite and reserved. She doesn’t really interact me that much but she does with the other two. I don’t know if she’s uncomfortable with me or what. I’m ignored when I say hi but they say hi to the kids. I understand the kids are more important and they need more car attention, but it hurts. When I told that co-worker I was going to the restroom, she didn’t respond to me and ignored me so I told the teacher she nodded. At least she responded. What is wrong with people? I’m trying my best to be nice and friendly. I’m used to being dislikes but come on! It’s like one of the co workers from my old job wasn’t too fond of me either. She barely responds when I am friendly. I started my new job July 26 and students started school August 3rd.