Campaign element execution: Marketing project XX is already being processed by

Hello!

We have an automated campaign where we have an campaign element with workflow WS14000061 (Transfer target group to channel). When we execute the campaign automation, it gets stuck on work item 2043 (Send Target Group for Element XX to Channel) of workflow WS14000061, and remains with status In Process and message "Marketing project XX is already being processed by"

Is there anything left to do to get the element to work?

Thanks for your help!