You have not provided any environment details. Please see #736. You can copy your environment details by opening User Settings and pressing on the build info at the bottom of the left sidebar. There are some known issues with client-side cache bugs related to voice states. If you refresh your client (Ctrl + R), they might just disappear. If not, please right-click on the community in which you banned the user and choose "copy community ID" and paste this ID in here, and I can take a look!
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Comment by Hampus