You may not be able to access the Curbside feature of one or more of your merchant accounts. It shows an error "404 Not Found"
You can try to log in to the reported merchant/business account by searching for it in the Business Search tab of the Engage Admin Dashboard for support. Log in as BUSINESS after finding it and then click Curbside in the left panel to confirm that the curbside feature is accessible for this merchant. If you are able to successfully access it on your side then it is probably a browser cache issue on the customer's side.
A caching issue with your browser could be causing this error and clearing the browser cache could resolve it. You may refer to the following on how to clear the cache for the most common web browsers: