Printing Password requested on IOS devices when none is set.

Hi all, using Acrobat X Standard.

I create and send out password protected pdf files to my team, but I do not use a permissions password. If anyone uses IOS to open the file, they are asked to re-enter the password each time they wish to print a specific page. As the files have multiple pages it is not practical to print the whole file but the pages to print are not necessarily following each other which means multiple password inputs. I thought I could work around this by using a simple permissions password, but this prevented printing altogether on windows?

Has any one seen this issue before, is it an IOS problem or Adobe?

Many thanks

Darryl