I have installed Bitwarden via the FireFox extension store. In a normal (non-private) window, I can navigate to the login screen of a site saved in my vault and press CMD+Shift+L on the keyboard to autofill the username and password.
This does not work in Private browsing for Orion, though it does in Chrome Incognito mode and Firefox Private browsing.
I already confirmed my vault is not locked and my extension/browser/OS are up to date.
Pressing CMD+Shift+L should autofill whether in private or non-private browsing.
0.99.128.1-beta (WebKit 619.1.11.111.2)
Sonoma (14)