This seems to be gnome-calculator. So, not Xmir.
Testing in miral-app (miral 1.2, Zesty with Mir 0.26.1) I don't reproduce the problem, so I think that's "Incomplete" for miral and gtk-mir until we locate the problem.
This seems to be gnome-calculator. So, not Xmir.
Testing in miral-app (miral 1.2, Zesty with Mir 0.26.1) I don't reproduce the problem, so I think that's "Incomplete" for miral and gtk-mir until we locate the problem.