[Ger-Poland-Volhynia] Umlaut on letter "y"

[K A]

I have come across a name spelled Byging (has an umlaut on the y). My great
grandmother's last name was Bieging. Could this be this same name?

I have never seen a y with an umlaut before. I'm wondering if someone can
shed some light on this.

Thanks,
Karen