Hello Gary,
Yes, this can happen. There's another method to hide this menu.
To do this, go to
Sellacious Backend > Settings > Global Configuration > Backend Display Options. Select 'Sellacious Backoffice Menu' in 'Main Menu'.
To create these menus go to
Sellacious Backend > Settings > Menu Manager. First Disable the 'Inventory Manager' form this view. If you want to create new menus, you can do that from here.
I hope this helps.
Thank You