Lost browser connection at close PDF form (Interactive form by Adobe) in IE11

We have implemented Interactive form by Adobe (Adobe Document Service) with HCM process in a SAP Portal local.

When launch the form through the Portal in the browser, this show and refresh correctly; but when close it, the browser connection are lost.

This issue begin when update Adobe Reader from version 9 to DC. In the past version (Adobe Reader 9) the forms work fine.

I have downloaded and installed the last patch of ACF following this note: 1402024.

This is the setting of Adobe Rader DC:

NOTE: if I enable the "Protected Mode at Startup" option, the connection work fine (no issue in the browser connection), but the form don´t work correctly (no refresh data from backend).

In this note 1538540 SAP Recommend set "Protected Mode" Disable.

Any help or comment will be appreciated.

Thansk!

Fabrizzio