Circular Dependency

This is very complex to explain and it is related to how the engine uniquely identifies each row in a table. If the table doesn't have a primary key, every column in the table  is used as the key instead. So if the first calc column works fine, but then the second calc column needs to use all other columns including the calc column, and vice versa. There are 2 solutions

best is to sort this out before loading using power query (get data). This is where this type of work belongs. If you must do it in Power Pivot, then add an ID key column to the table and set that as the primary key (I think there is a menu item for this, but I have never done it - see previous point)