samba: no permission for USB drives

I set up a samba server with several drives.
everything works fine with an internal drive - ir can be accessed from win10.

but when trying to access a drive that is connected via USB, I can see and select the drive from win10, but trying to connect results in a message that i don’t have permision.
the server settings for both, the internal drive nd the USB drive, are identical.

does the USB drive need special settings?

Can you show your working smb.conf and the mounted filesystems?

cat smb.conf
mount -a

seems to work now.
looks like samba couldn’t follow a symbolik link of the exported drive. I thought I had tried that before. But I did as well an update.

Glad you got it sorted. Thanks for the update.