Unable to open PDF form created in Acrobat with PDFPen

For my new laptop I purchased PDFPen to replace an aging version of Acrobat Pro. However, I am finding that it does not seem to do well with with forms I receive that were created with Acrobat. I have always had this issue with Preview, but was hoping PDFPen would do better. One form I received from a state agency just gave me a message basically saying that the form was not compatible with my PDF reader. Had to download Acrobat Reader to get it to work. Any thoughts? Am I missing something? Would the Pro version of PDFPen perform better? I did the Smile support site, but it was not helpful. Thanks for any help.

Some of the acrobat PDF have security build in for digital signatures and certificates etc. Unfortunately it’s Adobe proprietary (I think).

Thanks. That is kind of what I figured.