If you go to about:support with the latest Tor Browser 13.0 no information is displayed there.
This is most likely an upstream bug in Tor Browser.
By design, Whonix doesn’t change the “inside” of Tor Browser.
(related documentation: Does Whonix Change Default Tor Browser Settings?)
Therefore the only way to see this fixed is if you report this bug upstream against The Tor Project, the maintainers of Tor Browser.