How to end a subscription:

When ending a journal subscription you edit the subscription and enter the Subscription End Date but you must also Close the subscription.

Search for your subscription 

Select the option to  Edit Subscription, on the second page you must enter the date the subscription ends.

When you Save you will return to the screen shown at 1 above with buttons across the top are for <New subscription>  <Edit> <Renew> <Receive> and the last button is <Close> 

Click on <Close> and this will stop the system predicting any more issues.  You will need to delete any issues which the system created for 2020 before you close the subscription.