Custom font not working.

Hi there I have tried all the support documents you guys have here but I can not get my form to display the text field using 'Open-Sans'

Its says it is using Open-Sans in the developer console but at the bottom it says font rendered Arial.

This is the form:
https://form.myjotform.com/61973295655570

It is already in open sans, I think you just need to add weight in it if you want it to look thinner.

font-weight: 300;

Result:

That's exactly the same font shown in google fonts.