Check focus assist isn't enabled:

  1. Click on the date/time in the bottom right of the taskbar
  2. Focus Assist settings
  3. Ensure this is off, or if "Priority only" is selected, you can customize the apps that are able to show notifications - make sure Wavebox is in the allowed list

Check notifications are enabled for Wavebox:

  1. Open the control panel
  2. Search for "Notifications & action settings"
  3. Locate Wavebox and click on it
  4. Ensure it's turned on and "Show notification banners" & "Show notifications in notification centre" are both checked

If both of those are enabled, there are a couple of other things to try:

  1. Clear all notifications, by clicking on the date/time in the taskbar and selecting "clear all"
  2. Restart the computer.