SLES 11.4 is old enough for its Samba to default to SMBv1 only. You've set both client min protocol and client max protocol, which only affect Samba when it's acting as a client, like smbclient.
For server-side, you've only set server min protocol, so the server max protocol is still defaulting to SMBv1. And because now min protocol is higher than max, smbd ...
Had the same problem many times with TPLink routers, they really don't do Linux.
The below is from my Archer VR600 set up, but very similar worked with a 8980
I mount my drive with an alias in my ~/.bashrc file
alias mount-smb='mount -t cifs //192.168.1.1/volume\(sda1\) /mnt -o vers=1.0'
Confusingly the volume is called 'volume(sda1)', despite there being ...
It can be mounted successfully and the access to files with smbclient is ok.
I suggested to add noserverino to mount options.
This option handles cases where the server can not generate a unique inode number for each file. In CIFS/SMB files are almost always accessed (opened) by name, and it is not required that a file system be able to preserve a persistent ...