Fern's window selector is active when Fern is the only open window

I am using Fern like so: Fern . -reveal=% -stay -drawer -toggle

When the buffer list is not empty but Fern is the only window, <Plug>(fern-action-open:select) still triggers the internal window selector. Strangely the indicator for the window is 28.

If I press a it replaces the Fern buffer as expected, but if i press b the Fern buffer remains while my cursor is now hidden somewhere else, not sure what's going on.

Expected behavior: <Plug>(fern-action-open:select) should replace the fern buffer if Fern is the only window rather than calling internal window selector

Thank you for the great plugin