I am missing something obvious, I just can't think what it could be.
I have exactly the same as you and I get just the one beam listing.
Can you try in a new file with nothing except the one beam?
You can export/import the schedule to save setting it up again.
Also what version and build of Archicad are you using.
I am testing in 25 build 3002 (I should update to 3011).
One of the forum moderators.
Versions 6.5 to 25
Dell XPS- i7-6700 @ 3.4Ghz, 16GB ram, GeForce GTX 960 (2GB), Windows 10
Dell Precision 3510 - i7 6820HQ @ 2.70GHz, 16GB RAM, AMD FirePro W5130M, Windows 10