Various problems with the user-sync plugin

Hi,

I have many problems with user-sync plugin:

– Some sites refuses to sync (when the initial connection was apparentely good – but without synchronization)

– some sites that appear in sync (synchronizing launch from the master) are not well synchronized… For example, a user should be an administrator, he finds himself subscriber …

The logs do not provide any information …

[2015-08-12 1:20:19 p.m.] 0-10 – ajax shares ***

In short, nothing works and it bothers me a little, I spent two days on this problem by trying different installations (including all fresh installation).

Some help would be appreciate.

Thank you and sorry for my english…

Laurent.