This Apple Watch requires a newer version of iPhone.

Hello, I just bought my new Apple Watch series SE ,and tried to connect it with my phone (my phone is an iPhone 11 Pro) when I tried to connect it, it said the Apple Watch requires a newer version of iPhone. I did my research and found out that I need version 16.0 to connect to my Apple Watch so I went to settings to update my phone, but as I was about to, I saw that my phone was already updated to iPhone 16 as I had automatic updates on. So I tried to connect to my watch again but was left confused as it kept telling me I needed a newer version, although version 16.0 is the newest version and my phone was already on that version. I don’t know what to do now and I am frustrated, could you please help.