Description of the issue

I tried the amfora on master (e42b24c as of this writing) and Shift + Tab doesn't seem to work at all.
Tab correctly cycles through the links but Shift + Tab expected to cycle backwards doesn't work, nothing happens when I press both keys.

Environement

OS: Linux - NixOS 21.03.20201209.e9158ec (Okapi)
Terminal emulator: st