Redmine

Hello.

Please tell me if it is possible to somehow solve this problem. I have Redmine 2.2.0. When I add observers to the issue and select one person (by checking the box), I want to select another person through the search, and when I find him, the checkbox placed in front of the first person is reset. That is, I can either manually select the people I need, but since the list is long, this is inconvenient. Or add via search, but then it turns out to add only one person at a time.