This is macOS and comes from the Capacities desktop app.
Prerequisites: For a Pro user who has AI capabilities turned on…
Repro:
  • Open up a new Page
  • Put the Page in Focus Mode
  • Press Command-J to start an AI chat
Notice: nothing seems to happen. If you go out of Focus Mode, the AI Chat panel is in fact open
Expected: to either show the AI Chat panel while in Focus Mode or to jump you out of Focus Mode to see the opened panel.