Digital signature creation causes all checkboxes to be filled

I'd really appreciate your help with a question I can't find the answer to after hours of Googling.  🙂

I sell medical fillable forms created with Acrobat Pro (NOT Acrobat Sign).  One of my forms has two sections that require entries and signatures by two different people,  the patient and the healhcare provider.  I set the digital signature signed setting so that when each creates the digital signature, the fields in their part of the form are read-only. 

I thought that setting would only restrict the each person from making changes to the other person's part of the form.  Instead, creating their digital signature causes ALL of the checkboxes in BOTH sections to be filled (on all platforms and devices). 

Is that the expected behavior?  If so, is there a different setting to restrict changes to the respective sections while still showing their checkbox selections?  Thanks so much for your help!