I met with Eric Perrin (ACS Product Manager @ Adobe) at this years Adobe Summit in the Customer Briefing center and he indicated that they were looking at bring the merging functionality from ACC to ACS. We really really need a solution to merge Profiles!

We have the same issue as you are describing.  Here is the workaround that isn't the greatest but it works.  I create 2 users that point to the same email address using the "+" in the email address.  When you use the + it ignores all the characters from the + sign to the @ sign.  So here is an examp...

How do I generate an AES Key for a Landing Page? 

Has anyone implemented this on Adobe Campaign Standard?What is BIMI?BIMI stands for Brand Indicators for Message Identification. It is a mechanism that you can use to have your brand’s logo displayed alongside your authenticated messages. This logo image may appear in the place of user photo profile...

We just create an Audience query the relevant profiles or test profiles and use that selecting or filtering.John

Administration/Channels/Topology/Topology - Default TopologyReview the rules that have been configured.

When I first was setting up reports I noticed it uses the Default Topology for sending.  We have our Default Topology locked down and so it was not sending out reports to subscribers.  Not sure if that your environment settings but I thought I would mention it.John

In your existing query step add additional data element.  Click Add an Element and Enter the email address into the first field like this 'email@address.com' and then name it.Next create a reconciliation step.  Under identification use your new additional data field element above for the source and ...

This may be the same issue we have been experiencing for months.  You can have support reference TK171660.  Does the log give you an IP error?  If so, this maybe helpful.  They have not found a way that I can fix it but there maybe a workflow that they can stop to fix the issue.John 

I have had this issue in the past and it was because the targeting dimension wasn't Profile.  It defaults to Real Time.  It is on the first page when you hit the create button for the event.  Unfortunately if it is wrong you will have to recreate it because it is not editable.John