Question
What to do if Compare Wishlist doesn’t work for non-logged-in users?
Answer
Proceed to Crocoblock > JetPlugins Settings > JetCompareWishlist. Then go to Compare and Wishlist Settings and set the Store type to “Cookies” in one or both of those tabs.

If it didn’t work, you could clear cache and, as a last resort, deactivate the third-party plugins – one of them could be the reason for such a problem.
If you want to save the “Session” type, you could add the WP Session Manager plugin. On particular servers, the session sometimes goes broken when you switch to another page. The plugin fixes that.

If you have WP Rocket (this is the plugin for caching and optimization), open the Advanced rules tab and paste such an identifier into the Never Cache Cookies section:
PHPSESSID
SSESS

Note. Sometimes the functionality of the Save the list for logged users option could be misunderstood. It doesn’t enable wishlist/comparison features only for logged-in users. It saves the wishlist/comparison data for the logged-in users, so they can return to the site after some time and see the saved products on the wishlist/comparison pages again. If the Save the list for logged users option is toggled off, users will see their wishlist empty each time they revisit the site.

That’s it! Just in case: the JetCompare&Wishlist functionality overview can be found here.