I found that people sometimes don’t put the high quality(fine or excellent) object to finish building.
It means if I only have high quality object which the building needs, I can not finish the build forever.
Is that bug or I miss something?
Its a well known problem. The devs are almost done with a building system revamp, coming in a few weeks, so don’t expect it to change before that. It’s possible to mod the entity files to remove variable quality on standard items, but its a lot of work.
Alternatively, demote your main crafter and promote a new one from the workforce for the duration of the building and you’ll get far fewer fine items.