"Clear all notifications" does not work

Your software

Your problem
When I click “Clear all notifications” it does not work.

These errors are showing in the log:
No log errors.

Steps I have tried to fix the problem:
I tried clearing cache.
If I hand click individual notifcations then they clear.
But the clear all does not work.

I had an email fail, and have nearly 2,000 notifications. Cannot clear individually.
Hoping there is a way to make clear all work.