Sometimes your Super Send fails to detect a reply. This commonly happens with Linkedin

You can always mark the lead as finished from the Leads page if super send misses something.

With linkedin this commonly happens when the linkedin credentials expire. You need to open the chrome extension and make sure there is a green checkmark next to their linkedin credentials.

Once you have a green checkmark here, make sure on the Senders page that you see your linkedin credentials. Test them to make sure they are working by clicking Test Connection. If they are working, then in the next hour, the Linkedin messages should be marked as a reply and no further messages will be sent to the prospect.