IssueTracker

Component used: PreferenceHeaderFragmentCompat
Version used: 1.2.1
Devices/Android versions reproduced on: Phone Emulator API 32

The problem can be demonstrated with the sample app from Androidx Github repository https://github.com/androidx/androidx/tree/androidx-main/samples/SupportPreferenceDemos

When used on a tablet, it it possible to use keyboard to navigate between header and detail fragment and inside each fragment.
When used on phone, once the detail fragment is opened and covers the header fragment:
Expected behavior: Focus moves to detail fragment. Keyboard allows to move focus inside detail fragment. Focus is constrained to stay inside detail fragment.
Actual behavior: Focus stays on header fragment. It is impossible to move it to detail fragment. Keyboard events are dispatched on invisible header fragment.

The attached video illustrates the problem: After opening the first entry (Basic attributes), I hit Keyboard Down three times to move focus down inside the list, without effect. If I back out to header, I see that focus has changed there to fourth entry (Dialogs) instead. If I repeat the same exercise and after three times down, I hit enter, the Dialogs entry from the header fragment (covered by detail fragment) is opened.