Hi Newbie 2013 and welcome,
Well, this is one of the issues of using InfoPath to edit list forms. When the list columns change the InfoPath form can break.
My recommendation would be to create a full-fledged InfoPath form and have it map the data to the list.
I believe we have a log on how to map Person/Group picker values to a list.
I'm going to ask Don to follow-up with that info.
More soon,
Patrick