I post mainly on Mathematics Stack Exchange, under my own name, and less frequently on other SE sites. I notice that, although signed in via Math SE, my posts on Academia SE go under a user number rather than under my name. This is not a big issue for me, but I don't see the need to be anonymous here. Is there a simple remedy for this?
You need to set your profile globally. When you edit your profile you will see two boxes. One that says "save changes just for this community" and the other "save and copy changes to all public profiles" at the bottom of the page. If you want all your profiles to be the same, chose the "all" box. You probably want to start editing from your math profile if that is the one you want to go everywhere.
There is a lot of information on the main meta. Maybe Don't force sync with my oldest account on my network profile but there is probably something better