Issue with signature field when creating an interactive form in InDesign

Hi, 

I spend a lot of time creating fairly basic interactive forms in InDesign. These generally consist of text fields, check boxes and signature fields. 

Typically the Signature field was created so that the user could add a graphic illustration of their own signature either using their finger on touch screens, or using their mouse or trackpad. 

No issues until recently when Acrobat Pro won't allow the finger/trackpad option and will only provide a digital stamp as proof of signature. I haven't edited any of my settings and I do these forms on a weekly basis. 

Can anyone tell me if this is a bug, an issue (and if so how to resolve) or if Adobe recinded some functionality on Acrobat Pro?

Thanks

K