Question about MySQL join on

Could someone help me understand why this does not work for me?

Thank you in advance!

Is your database named store?
Because on the working queries you refer to tables by store.orders while in the failing ones there is no database prefix.
You need to set the database manually.

USE store if store is the database name.

You haven’t indicated which database to use.
you can add

USE sql_store;

to the start of your query if the database you are querying is sql_store