Since today, login to the Forum is no longer possible from Windows 7. I tested several browsers (Firefox, PaleMoon, Chrome, Chromium, Opera), and all are declared as unsupported. The Forum can be opened, but no login is offered any more.
What has happened there?
Unannounced (uncontrolled?) forum software (Discourse) upgrade.
A lot of other things changed too - reply form layout for example.
Was this ever tested? The intro page shows an option to upgrade to a supported browser, but, for Firefox and Chrome, it just reinstalls the versions already installed in Windows 7 - the last ones supported there, while Brave cannot even be installed at all.
This is just a bad regression, because it removes functionality needed by users relying on Qubes to provide a secure environment for the last usable version of Windows, without forewarning and without providing an alternative.
Furthermore I am writing this with Firefox from an AppVM running under Fedora 44, and I see no improvement in normal Forum usage provided by this change. Even, the reply form is now less flexible. So, what the heck?
For this reason; I urge you strongly to fall back to the previous version of the Forum software, or, at least, to provide an option to do so.
Caution: The following text is a private opinion about software engineering. I do not wish to offend anyone by this, but instead just hope to start a bit of discussion or, at least, cogitation. So, please, before reading on, just take some valium, or so … 
When changing software, existing functionality should always be retained, unless this would create a severe security risk. Dropping functionality is just bad software engineering and therefore should be avoided by all means. If a new function is added preventing the use of some old interfaces and functions, this change should check the environment before dropping existing functions. If the environment will not allow to use the new functions, the old structure should be kept, perhaps even at the cost of not performing the intended upgrade, or the old and new structure should be kept in parallel, selecting the appropriate one according to the present environment. If this is not possible for technical reasons, the upgrade should be aborted, possibly after a suitable warning (which should be displayed just once, not on each further activation of the software).
Neglecting this rule is just a sign of bad software quality, and allowing that is a sign of lacking quality management, because it shows neglect of the consumers’ needs. Qubes, with its extremely high quality, deserves a much better presentation of itself to its users!