Auto Lock not disengaging after activity

I have a brandnew Vivoactive 4S. There are 4 options within System to choose with Autolock:

1. Off

2.Always

3. During activity

4. Not During activity

I opted for autolock during activity to ensure my data screens don't swap or close when my cuff moves over the watch during an activity however I have found that autolock does not disengage after the activity has been completed.

Example - watch is switched on; I opt for a tracked walk (autolock during activity is my system setting). Autolock works as it should but once I complete the activity (ends it), the autolock stays on and don't disengage.

Can this be fixed please? If I choose Autolock during activity that is what I expect.

Thanks!