It will be difficult to really comment why the two are not working without seeing the setup of Enrichment.
At present what I can suggest you is lets say table1 is the schema with email address fields and table2 is the transaction table.
My guess is that when using Enrichment, you have taken two query activities pulling in data from the two tables and trying to link them with help of Enrichment. Currently the primary set has been selected as table1.
Try reversing the condition. This time create a fresh Enrichment activity and disable the older one. In this new Enrichment activity select table2 to be the primary set and then create a link with table1. When selecting type of link make use of option 1:1
Output of this Enrichment can then be fed to a Change Dimension activity giving you table1 as the targeting dimension.