Oh Lord, that's lucky, because I stopped understanding anything...
Additionally, if you want it in the FMCB settings (FMCB configurator),
there is an option > Go to Browser:

I recommend setting it to "Force OFF".
Then it should not "throw" us to the memory card browser, but to the main screen.
Regarding FMCB, did you download the beginner package or pure FMCB?
Did you select Normal, Cross, Multi, etc during installation?
EDIT: Oh, and I found a version that should handle the memory card in both slots:
https://www.psx-place.com/threads/hwcs-osdsys-launcher.30258/page-4#post-267180 .
Additionally, if you want it in the FMCB settings (FMCB configurator),
there is an option > Go to Browser:

I recommend setting it to "Force OFF".
Then it should not "throw" us to the memory card browser, but to the main screen.
Regarding FMCB, did you download the beginner package or pure FMCB?
Did you select Normal, Cross, Multi, etc during installation?
EDIT: Oh, and I found a version that should handle the memory card in both slots:
https://www.psx-place.com/threads/hwcs-osdsys-launcher.30258/page-4#post-267180 .