We cannot reproduce the issue locally, so we'll need some more information:
1. Which is the exact Sitefinity version you are using?
2. Which is your browser version and can you reproduce this behavior in other browsers?
3. In Classic mode, can you click Edit/Trashcan in both controls after the PollID is set for one of them?
4. Have you modified any of the Polls templates in any way?
Thanks for your cooperation in advance.
the Telerik team