In Gonville fonts, there is no " + " when I write the Time Signature.

Hello, I found one problem of the Time Signature.
When I use Gonville font, for exanple, I write the time signature " (1+3)/4", MuseScore writes "13/4".
Only gonville is short of "+". Emmentaler and Bravura is no problem.

I like gonville, if the problem is fixed, I will be happy.