System wide autofill

Sometimes when I'm typing my email, it will be autofilled without deletin what previous text was there.

I.e.

john.doe12@gmail.com

I will be typing `john.doe<cursor>` and then will have the field show `john.doe12@gmail.comdoe<cursor>`

It's not specific to one app, so I'm not sure where to look for this setting

It makes it even more frustrating because my work email is

john.doe@work.com so if I try to type that it, it sometimes autofills the broken personal email (john.doe12@gmail.comdoe)

Both my macbook pro's have this issue and have had it for a while (across multiple OS versions) - I always update at least one of them when a new os comes out