I believe that, when I book somebody with an active recall, CO asks me what to do with that recall. Great feature, but it doesn’t work when somebody books online. After acknowleging, there is no dialog-window to ask me to delete the active recall.
Thanks for pointing this out and you are correct after you have acknowledged an appointment it should trigger a message asking you if you would like to delete the linked recall. I have submitted this to be fixed and all being well in the next update it will address this issue.