I just got the reply that it's not a bug that the TwinApp version of WhatsApp doesn't work with our fingerprint. It has never worked and never will because of a limitation in our software.
To solve your media issue, I need to know for sure if you have Media visibility enabled or not.
I also need to know if you're only searching with our gallery app or if you're also using the file manager.
Can you see images in these two folders?
Main WhatsApp gallery is located internal storage -> WhatsApp -> Media -> WhatsApp Imagaes
TwinApp WhatsApp gallery is located internal storage -> TwinApps -> WhatsApp -> Media -> WhatsApp Imagaes