OK, here’s the part that I think is causing the confusion: that entry in the config file is taking whatever is located at /mnt/pve/wdmycloud and bind-mounting it to /media/share inside your container. The permissions on the host get passed through to the container, so if you’re using an unprivileged container (that’s the default) the user IDs are offset by 100000 (meaning the host would have to set the owner of that directory to 100000 instead of 0 for root inside the container to have access.
So, forget all that and let’s just use SMB, which sounds like it’s working. Comment out the line in config file and inside the container, edit /etc/fstab and we’ll put in a version of that mount command that will run when the container starts. Add a line like this:
//192.168.1.110/public/Multimedia /media/share cifs rw,vers=3.0,credentials=/root/.examplecredentials 0 0
Save and close the file and then run mount -a or reboot the container.
This is just one of many ways to handle this, but I think it’s the most direct based on the situation.