Hi Guys,
we have a pretty old on-premises SQL-Server based CRM system. To access the Data easily within MS Power Platform tools, we installed the on-premises Data Gateway. As we don’t want to modify the original Datamodel, we are planning to solve this via Dataverse Virtual Tables. The Virtual Connector Provider (VCP) Preview looks like a good way to deal with it.
I followed the instructions from https://docs.microsoft.com/en-us/powerapps/developer/data-platform/virtual-entities/create-virtual-tables-using-connectors and now I can see and create all the tables and access the data.
However, there are a few strange behaviors and one big problem. I know the feature is still in a preview... but maybe someone can help me out here. Maybe it is not connected to VCP at all.
Problem:
Relationships between Virtual Tables and native tables are not working. As a result, a can only lookup correctly 2 of 3 Virtual Tables. Adding a record only saves 1 out of 3 lookup values.
Let me try to show you the facts:
I added 3 Tables via the VCP (yellow)

and created 1 native table (blue). My goal is, to connect those via the native table.
So I created 3 lookup cols in the blue table.

They also have (seemingly) correct relations to the VCP tables

I added those columns to the main form as well:

And now the strange behaviour kicks in.
When I try to add a record through Dataverse the main form is invoked:

The lookup for the first column works just fine. Unfortunately, the lookup for the second column shows only 1 out of 3 records:

In Dataverse, I can see all 3 records..

Also interesting: When I try the advanced search, the result is one different record:

The lookup for the third column works good - it shows all records:

So just before I hit the save button, the complete record looks like this:

Once, the save button was hit, the second and the third column changes:

Dataverse shows the same result:

Does anyone have a clue what I am doing wrong? Why is only one out of two values stored correctly?