SPFx: The drop-down menu of & # 39; office fabric ui react & # 39; it does not work in the latest version 1.6.0 of me sharepoint generator.

I built a web element using SharePoint framework with the SharePoint generator version 1.3.4 with drop-down menu multiselect = true in the user interface and then I updated it to version 1.6.0 now the drop-down menu does not work. (The check box does not reflect the actions marked and unchecked in the user interface).

Can anyone help me with this problem?
Thank you!