At least in the Hungarian locale a decimal comma is in use instead of a decimal dot. When designing IIR filters, the "End of Pass Band" has an initial value of "0.3" which is wrong as it should show "0,3" (but this is not a big issue just related). The "Start of Stop Band" is set to "0.5". And the problem is that it's impossible to change these values because a decimal dot cannot be entered at all. A decimal comma can be entered but due to some incorrect validation logic the value is not accepted and the filter is not recalculated after pressing the "Design" button.
At least in the Hungarian locale a decimal comma is in use instead of a decimal dot. When designing IIR filters, the "End of Pass Band" has an initial value of "0.3" which is wrong as it should show "0,3" (but this is not a big issue just related). The "Start of Stop Band" is set to "0.5". And the problem is that it's impossible to change these values because a decimal dot cannot be entered at all. A decimal comma can be entered but due to some incorrect validation logic the value is not accepted and the filter is not recalculated after pressing the "Design" button.