By "detailed" book details panels, do you mean the window that pops up when pressing i? Is there more than one?
I suspect that the cover has the keyboard focus, which may be for a reason or maybe not. Perhaps Kovid can shed some light and depending... might be amenable to changing the behaviour slightly?
Adding the following code to class CoverView / def __init__ in widgets.py seems to do the trick:
Code:
self.setFocusPolicy(Qt.FocusPolicy.NoFocus)