If you search something, then after that, edit the search criteria in the left panel, nothing changes. This happens for all users and all browsers.

Diagnosis
It seems that the behavior can be reproduced in the following cases :
The problem can be reproduced on a fresh install under either of these conditions:

• The Workbox plugins are disabled:
  • Workbox - Common Plugin
  • Workbox - Confluence Provider Plugin
  • Workbox - Host Plugin
• OR, if Confluence Admin > In-app Notifications is disabled