Win10 Acrobat Reader Long path names (\\?\UNC\ path)

We recently enabled a GPO to allow long paths, this fixed our issue where people got error messages while trying to rename/remove the files.

Files also open properly when using Office applications.

When we try to open a PDF file with Acrobat Reader nothing happens.

In the Eventlog a error message appears (Appliction error 0x0000005 I believe) which says path not found.

The path it uses to find the look like this: \\?\UNC\server-name\long\path\to\file

We use the latest version of Reader/Windows 10 Pro

Is this something Acrobat reader does not support (yet)?

Or is there a setting somewhere I need to change?

Any help would be appreciated.