What if you use a dot (period or full-stop, depending on what you call them in Sweedish). When I use a comma in North American English InDesign, the comma is replaced with a dot, and the display shows 11.3 points.
What ar the comma-period settings in you OS? Does it interfere?
Here in German, I can use . or , equally on these fields.
It is not very comfortable to use a . instead of a comma with many keyboards. I hate it too, if I use a program which requires . instead of , in numbered fields on a German Keyboard, it is really a break and does not allow fast work.
I have no experience with German keyboards. In English, comma and period are next to each other.