Planets that "eat" population and never increase above 1 population

1 Does the planet have a leader?

If no then nothing you do will make it grow population.

2 Is the planet a Precursor World?

If yes then you have to build housing as Precursor Worlds are limited to one Pop till you do.

If 2 is no then you should be able to grow or build pops. 

Synthetics need Promethium to grow but that does not sound like you problem.

If nothing above fits your game then there is something wrong with your game.

Try verifying files first then report if it still happens. 

Let us know either way.

Yes, the planets have leaders.

The planets are not precursor worlds.

I have plenty of resources and I play synthetic.  All my other planets with leaders allow me to increase the populations.

All of this occurred in various prior versions to the one I got today.

I verify the game files almost every time I want to play the game.

Had to ask those questions.

They are the things most misunderstood about pop growth.

If you can go to Discord and post this in the Supernova Sitrep channel it would help.

If you want to post your save game I'll check it out.

Pinged you on Discord OP posted a save there.