Need some advice!

So Saturday as I'm sitting on the couch. I look over and I'm getting a call from none other than my ex husband. It had been ring a while before I answered it. Well I answered and said Hello and as soon as I did he hung up. Didn't even say a word.

I haven't heard from him since maybe spring and we have been divorced for a year now. We don't have any kids.

Definitely not thinking it's a butt dial cause I know I'm not in his recently contacted. I just wanted some other opinions on what y'all think?!