The compare at price is just one solution of many that are available to you. Please check out our official documentation on the European Price Indication Directive to learn more about other ways to implement pricing updates.
I trust that will offer more context into how to use the compare pricing tool amongst many others to make this work on your store.
Hello, I made a tutorial on how to fix this. Watch it here : How To Solve ‘Compare-at Price Not Showing’ Problem On Shopify https://youtu.be/Z66eX-cfCFw