Hello Kim,
Can you elaborate what is the issue you're getting when logged in as a seller?
Kindly check Seller category, in which the user is registered if in the category the seller group permission is allowed.
To check this, go to Sellacious Backend > Categories > Seller. Select the category in which sellers are registering and in Seller Attribute Tab 'Seller' group should be selected.
I hope this helps.
Thank You