When using JIRA Software, I can see that there are unread notifications like in the screenshot below:

But when I click on it to open the notification drawer, it just comes up as a complete blank area with no tabs or anything apart from the X to close the drawer as seen in the screenshot below:

System and browser information below if that helps:
OS: macOS Catalina 10.15
Machine: MacBook Pro (15-inch, 2016)
Browser detected in: Chrome (Version 79.0.3945.88 (Official Build) (64-bit))