A BUG?

[Parasite]

I put a single WobblyBob troop in the queue and put it on hold. Then sort by Build and the blank ones come to the top.

All right, I just wanted to use "WobblyBob" in a sentence.

[Suicide Junkie]

They don't show up at the bottom unless you name the dummy item "zzzz!" or similar, but they certainly don't show up at the top.

That being said, if you add things to the queue from the queues list, the sort order does not immediately change (that would be a pain when the thing you are looking at jumps around).
You can close/reopen the window or just click the list header again to trigger a resort.

[Fyron]

I usually just press the "upgrade all facilities" button. Clicking a column header resets the memory of the last 3 parameters for the sorting, doesn't it?