Append Queries create duplicate values

I have two table, one is coming from Teradata warehouse (Project ID, Project Name, Type, Cost Category, Cost, Funding, Status) and another table is coming from Excel (also with Project ID, Name, Type, Cost Category, Cost). Type includes two types: capital and operating. Cost Category includes: hardware, software, non-labor, interest. After the second table is appended to the first table, in the data model, when I dragged the cost category to a slicer, it shows duplicate for each cost category value (hardware, software, non-labor, interest, hardware, software, non-labor, interest) , but the type does not show any duplicates (only capital and operating) in another slicer. Does any one experience this problem? If so, do you know how to fix this issue?