One thing that has bitten me in the ass is that duplicating a symbol in schematic copies ALL attributes, including the "exclude from BOM" one.
No need to say that the duplicated symbol in question was not meant to be excluded from BOM.
That wouldn't have been a problem if there was a clear indication of a symbol not being in BOM, either on the schematic itself or in the symbol fields table. It's on neither.
And an other(s) comes up, why those attributes are not copied from MY symbol...
I mean, this is a clone operation with altered attributes, as you like to have a pure library symbol copy, what is complete different operation. So request this as a feature.
Or simple select the symbol from the library, as a workaround.
Hp