This article describes how to flush a stuck park button (park button is red, even though there is no call there)

Step-by-step guide

Log into https://portal.sipvoice.com.au/ and select the Tenancy you wish to modify:

1. Ensure you're in the right tenancy, then click the 'Apps' button, the '9 dots' next to the tenancy name (Picture 1).
2. Click on the 'Debugging' app (Picture 2).
3. On the left, select 'Presence' and then sort/search/show all the entries so that you can see the Park Subscriptions: *3701, *3702, *3703. Click the 'Flush' button at the end of the row (Picture 3).

The Park subscription(s) have now been flushed.  Confirm that the 'stuck' park button works as expected. 

Picture 1:

Picture 2:

Picture 3: