We are going to need to implement auth webflow support for flatpak remotes in gnome-software as RHEL flatpak remotes are going to make use of it. The plan is to get it ready for 8.3.
Upstream MR: https://gitlab.gnome.org/GNOME/gnome-software/-/merge_requests/467
... and the fixes above are now backported to gnome-software-3.36.1-2.el8 build
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory (Low: gnome-software and fwupd security, bug fix, and enhancement update), and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHSA-2020:4436