I have multiple jobs where all the jobs are full but only three or four workers are on duty. How do I fix this?
Colonist, just like in real life move shifts, when they are off duty they sleep, educate, entertain themselves,... You can almost never have full number of colonists working for a longer period of time. Unless you have Consulate/Capitol lvl. 2/3 you cant fix this.
Another things is that they are off duty when walking from place to place. So the closer together your colonists' houses, jobs, entertainment, and education buildings are, the less walking they have to do and the more they can work