There are 3 possible causes.
(1) The product (or blog post) to which the tag is assigned does not exist.
Please set the tag on the product (or blog post) and check again.
(2) the status of 'RuffRuff Product & Blog Tags' is set to 'Disabled'.
Go to the application settings page of 'RuffRuff Product & Blog Tags' and activate the status.
(3) The state of the 'Tags' application in the Theme Editor is 'disabled'.
Please check if the 'eye icon' in the 'Tags' app in the Theme Editor is grayed out.
If this does not solve the problem, please contact us.