Hello,
This is expected behavior if you are not logged in.
The UIs are available to logged in users with the correct capabilities.
If you want to change the error message displayed, please consult the manual under Frontend -> Frontend UI WordPress filters -> Shortcode rendering error messages. This will give you instructions on how to use the wallets_ui_text_shortcode_error filter.
The manual is the PDF file in the bundle download of the plugin available here: https://www.dashed-slug.net/downloads/
If you are logged in and you still see this error, it is due to your server side cache settings. Simply exclude the page with the wallet shortcodes from your caching plugin.
with regards