Should my foot be able to move in skates?

I just got fitted for a pair of new riedell skates but I wanted to ask about the fit before purchasing. When I tried them on they were snug all the way through except a weird feeling in the heels. It wasn’t wiggly or loose but I felt like when I pointed my toes or flexed my ankles it was like my heel would lift just slightly from the footbed. I don’t think I could go a size down lengthwise and the other brands my pro shop carries are way too wide. Any tips, and should I even be worried about the tiniest bit of heel room?Thanks!