Password prompt for primary password appears while using a different application
I have set a primary password in Firefox. Sometimes, the password prompt appears out of nowhere. For example, I have Firefox running in the background while I'm using a completely different application, and suddenly, the password prompt appears, asking me for my Firefox primary password.
This is very distracting, so I'm wondering if it's possible to configure Firefox to ask me for my primary password only while I'm using it. I don't care if the prompt appears as soon as I start Firefox, or whenever a new page is opened that requires a password. The only important thing is that the password prompt doesn't distract me while I'm using a different application.
Thanks in advance for any hints.