Hello,
I suppose you were using the CEF (Chromium) to render your pages in FreeMASTER. The version 3.2 brings the new version of CEF (99.2.10+gfecf7ca+chromium-99.0.4844.51) - so I suspect the change in CORS handling might be related to this update. FreeMASTER itself does not do anything special about page sources, origins and redirects. (Well, it does, but only a minimum needed to handle a special fmstr:// protocol which fetches files from the target board).
The FreeMASTER version 3.2 also brings the Microsoft Edge WebView2 component which is also chromium based. Can you try the behavior in this browser?
If this does not work, please describe your problem case in more details, so we could repeat the issue locally.
Thanks,
Michal