Not necessarily. Ego is a sense of self. If you have an accurate sense of self, then you know what you know and what you don’t know, to some extent, but more importantly, you understand that there may always be things you don’t know and you are willing to listen and learn.
However, if you are insecure and have a poor sense of self, you may overcompensate by acting as if you know more than you know. You can come across as overbearing and a know-it-all, and indeed, this could keep you from being open to learning.
Having a poor sense of self shows up both as presenting strength where none exists, or as showing weakness where strength exists. You might over-present yourself or under-present yourself. I think that mostly it is in the case where you are pretending to be something you are not that you may cut yourself off from learning new stuff, since that would make you look weak if you think others expect you to know that.
But a healthy ego knows itself, and does not puff itself up or diminish itself unreasonably. In either case, it is open to learning.