The release notes for the recent maintenance patch say:
However, my base on Hortus-d (VH-331d) just had its workforce drop to 0, after being at 200 last week when I settled it. The population report shows 0 workforce available. So either that bug isn’t fixed after all, or there are two bugs to do with population being at 0 on newly settled planets.
(I think there had been a base on there before? So it’s not newly settled in absolute terms, but there was nobody there any more when I landed.)