Slack invalid token? UI won't allow for channel selection

Hi,

Attempting to add alerts to a slack channel, but I'm receiving invalid token and am unable to select or create a channel in the Metabase due to a scroll constraint.

Did you follow this doc

I was able to figure it out after I had changed the name of the channel in Slack - it broke the connection.

I am still having trouble with duplicating alerts. One is from 'MetaBot' with a hyperlink to the alert and the other is the from 'Metabase' with an image of the first page of the alert. Is there a way to disable one or the other?