"unable to connect" if Firefox GPOs configure proxy settings

I am using Tor browser on a Microsoft Active Directory joined computer. Domain admins set up Group Policy Objects configuring Firefox to use a proxy auto-configuration script. That setting from GPO overrides automatic Tor Browser setting to use localhost:9150 and when I try to navigate I get "Unable to connect" error page. Tor Browser connection settings are locked by the GPO, as it is in the installed version of Firefox, and I cannot change them manually.

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Username: kT3Ycp9jwm