Creating pdf/a: user has no access rights to created file

Windows machine with two local users: Administrator and (lets call him) "user".

I put the user account into the admin group. Then I installed Adobe Acrobat DC on the machine and activated it.

When the user converts a document into a PDF then he can access that PDF afterwards fine.

If the user creats a PDF/A (not a normal PDF) then the file gets created at the target location but the user does not have any rights to it. In fact, looking at the windows file rights, the user is not even listed in the ACL. Only the Administrator and SYSTEM.

For whatever reason Disitller must create PDF/A files with different file rights than normal PDFs.

I have no idea why that is or how to change that. 

Anyone any advice?

Thanks.