Receiving multiple call notifications in Pagerduty app after incident is acknowledged.

Our single responder keeps receiving extra calls after acknowledging the incident in the Pagerduty app. Instead of one call, it ends up being four calls back to back even after the issue is resolved in the app. The calls won’t go away unless the call is answered and the incident is resolved in the call.

Why is this happening and is there any way to fix this issue?