Hi! Here you are creating a custom association. This is not a loading dialog but an indicator for the level of association between the two tables. In your case it is low and this is because your left table has, e.g., 1000 values (1-WEB, 2-WEB, ..., 1000-WEB) while the table on the right has, let's say, only 50 unique WEBs.
Bottom line - this is not a loader and don't wait for it to move, it never will.