User password changing is not working in Groupshare 2014 (all fine in 2015)

Hi,

We encountered a problem when trying to change user's password in Groupshare 2014. It looks like API responds with result 200 OK, but password is not changed.

When testing on Groupshare 2015, all works fine. Please take a look at request sent directly from browser.

Is there any workaround for Gs 2014 ? Or do you plan any fix for that ?