Connecting 2 tables thru a master data table

I have this setup :

MD_Carrier is de master data table with which I connect table 1, Case, with table 2, ForwardersDPMO.

Done these things before and always worked just fine.

However now strange things are going on.

These are the carrier in all 3 tables separate :

As you see Table 1 has more than the MD table but that should not be a problem.

And table 2 has exactly the same Carriers as the MD (table 2 was the input for making the MD table)

Normally you would be able to put all these fields in 1 table right?

Well if I have from MD carrier and from table 2 Forwarder in 1 table :

What causes this?

Because this also gives me stange numbers or no numbers if I use the MD carrier in visuals and pull in amounts from table 2 and fields from table 1.