Slowdown when tapping notification from lockscreen

[heilong]

I've captured the log. Locked the screen, then woke the phone, double tapped the notification, entered PIN.
According to the log, the notification flow was triggered executed immediately after unlocking. All that flow did was to set a global variable, and finished really quickly. After 3 seconds with no events in the log, the "user present" flow was triggered. So unfortunately the log doesn't explain the 3-second slowdown.

Disabled all SmartUnlock flows, switched to secure lockscreen CM profile manually. Double-tapped still ongoing SmartUnlock notification, entered PIN, Automagic immediately opened and shown me the flow that added the notification. So, no slowdown.
Created a new empty flow with "Notification on statusbar selected: all ids" trigger, enabled it. Slowdown is back. Also tried listening just to this particular notification's id, no changes.

Other apps (e.g. Gmail) appear without slowdown.

It appears that for some reason in all cases adding a flow triggered by "Notification on statusbar selected" causes a slowdown when such a notification is clicked from a secure lockscreen.