Cannot delete meetings in Skype For Business Web Scheduler

Hi,

In Skype For Business Web Scheduler I cannot delete any meeting displayed in 'My Meetings'.

When opening these meetings, the message 'You can’t make changes to this meeting because it wasn’t created using Lync Web Scheduler.' is displayed on top of the page.

Clicking the 'Delete' button doesn't do anything.

Can you tell me how I could delete these meetings please?