Disable onboarding prompt ("Open previous tabs?") FF 117

We've recently migrated our Electron app to running a firefox kiosk application on our IoT devices. And one thing that has been happning is that this "Open previous tabs?" banner shows up after closing/reopening firefox. We've configured the following: lockPref("browser.sessionstore.max_tabs_undo", 0); lockPref("browser.sessionstore.max_windows_undo", 0); lockPref("browser.sessionstore.max_resumed_crashes", 0); lockPref("browser.sessionstore.resume_from_crash", false); lockPref("browser.sessionstore.collect_session_storage", false); lockPref("browser.sessionstore.restore_on_demand", false); But the banner (which seems to be for onboarding users) does still appear, does anyone know what preferences we are missing?