Cannot vote already voted posts (everything is checked)

Hello.
In my case also only one vote is allowed. I mean, I cannot vote a post if it has been already voted. So all posts have just one vote.

Tried to disable all other plugins and it still not working.

Only registered users are allowed to rate, and are logged by username.

Any help?

https://www.ads-software.com/plugins/wp-postratings/