Backward tabbing (shitf+tab) in panels does not work (act as tab)
In builder 3.31.1-84-g559a94bf flatpak-nightly I get a tabbing behaviour where pressing "Shift+Tab" moves the focus forward rather than backward. This happens in all the glade widget properties tabs.
Note that there is a second bug in the a11y tab causing an alert to be issued. This however can be reproduced with glade itself, while the "Shift+Tab" issue is specific to Builder (glade#343)