Connecting a Refrence table

Hi, I have created a PIN refrence that includes an ID, year and a custome coulumn (=Number.ToText([PIN])& Number.ToText([Program Year]). ) 

The PIN refrence table is created by appending a few other tables: 

// Load the first table and select the column to append
Source1 = Table.SelectColumns(T1, {"PIN","Program Year"}),
Distinct1 = Table.Distinct(Source1),

// Load the second table and select the column to append
Source2 = Table.SelectColumns(T2, {"PIN","Program Year"}),
Distinct2 = Table.Distinct(Source2),

......

// Combine the distinct values from all tables
FinalTable = Table.Combine({Distinct1, Distinct2,Distinct3,Distinct4,Distinct5,Distinct6}),
// Get distinct values from the final table
FinalDistinctTable = Table.Distinct(FinalTable),
#"Removed Duplicates" = Table.Distinct(FinalDistinctTable),
#"Added Custom" = Table.AddColumn(#"Removed Duplicates", "PIN_Year", each Number.ToText([PIN])& Number.ToText([Program Year])),
#"Removed Duplicates1" = Table.Distinct(#"Added Custom")
in
#"Removed Duplicates1"

I have also a Fram Type reference table that includes all the different farm types. I created a table and just listed the different type of the farms. 

I connceted the Farm Type table to all other tables ( one to many -single).  I created a slicer from it there is no Blank box in the slicer and works fine. However, when I conncet the PIN refrence table to the other tables ( one to one- both; it does not give me any other option) the Blank box appreas in Farm Type slicer. it is something with the relastionships, but I cannot figure it out. Could you please help with this.