Can’t set master password in the tor browser

I’m using the tor browser Version 78.11.0esr in whonix 15, everything works, except that I cannot save logins in the tor browser because every time I try to setup a master password, a popup window appears, throwing me the following message : Unable to change Master Password.

Now I tried several things, which didn’t work out :

  1. Disabling Tor private browsing mode and setting it to Remember history. (I disabled it via: Preferences > Privacy & Security > History > Tor Browser will > Remember history).
  2. Setting security.nocertdb to false (which was set to false by default, so I didn’t have to toggle it).
  3. Restarted the browser

Any idea on how I might be able set this Master Password ?

PS: I know it’s generally a bad idea to store passwords in the embedded password manager of browsers, but this particular browser is isolated in a whonix VM, which can only connect to the .onion site of my email provider. So I won’t be searching the internet with this browser or doing anything else than accessing one unique website. That said, I have carefully thought about the reason why I want to do this, so please don’t bother advising me otherwise.