problem in saving unicode characters

Hi,

First of all thank you for the Great plugin!

It seems like there is a problem in saving unicode characters like Persian language.

In the membership levels area where you set the “Description” and “Confirmation Message”, if you write something in Persian language and hit “save level” button, it changes the words to question marks.
For example if I write this -> “????” it gets saved like this: “????”

I would really appreciate it if you fix this problem, cause I want to translate this to Persian language and use it in my site.

Regards.

https://www.ads-software.com/plugins/paid-memberships-pro/