Though it is clear that population drop has been a recent problem on the web app, I wanted to point out it's also a problem on the Android app.
I'm running the latest version of Android on a pixel 4 with the latest download of my colony available and I'm having the same issue everyone else is discussing: population will dissapear in large numbers at time of payroll after the first 100 colonists appear.
As has already been pointed out, this is not a problem of not having enough healthcare, entertainment, employment, or education. Clearly a bug in the game.
Android population drop
#1 2019-12-30 18:15:25
#2 2020-01-04 00:43:15
The update helped some... I can finally get a population above 200, but I still lose 100 plus people instantly every couple paydays. I have 20 Landers to just try to slowly increase the total number of people. Definitely still a problem here. Game never used to be like this.
#3 2020-01-10 16:57:22
I updated to v.1.2.0 and checked all of the current colonies (4 pre-1.0, 2x UE red planet, 1x Insectoid Sugarland, 1x LIS abandoned world; 2 post 1.0, all UE earthlike), to verify if the colonies are now stable. I have 2 devices I run on. #1: Android 5.1.00.1.35; #2: Android 7.1.1.
My pop drop is similar and different to the others. I will lose around 450-500 each payday. Only about 50 end up as deaths. The rest just disappear from total pop (no emigration--they just poof). However, this is only on my pre-1.0 colonies. Insectoids is fine, since within about 1 to 2 minutes they produce the missing colonists from the mounds. The biggest kick is with my human colonies. All of them have 2 cloning facilities. LIS has to have 150 landing pads to keep pace with the missing people. My smaller UE base (33k pop) needs 35 landings pads to keep pace. My larger colony though.... 205k pop, 275 landing pads. Also, all of the deaths are only minors. I've had 32k births, but I only have 14.5k minors. I'm actually having to "gear down" my colony to build more food, medical and education (as in get rid of higher tech buildings and move back to lower tech ones). So, I don't know if that is a cause of the "instability" or not. I've tried the "turn off housing and see if it stabilizes" trick--they just get mad because they are homeless.
All of the new post 1.0 colonies have never had the issue at all. Never lost a single colonist. They are just turning the game into "Rabbit Simulator 2020" (1 colony has 12k pop, 2k adults and just under 10k minors; the other one has 4.5k pop, 1.1k adults and 3.4k minors). Neither of those 2 can progress. To much building of food, med and entertainment (money as well, except I need the workers in food and med). So much in fact, that the one with 12k pop owes over 350k in taxes that it can't pay for. The other is not as bad only owing a bit over 20k in unpaid taxes. I almost wish they would mass disappear like the others to self-cull their populations.
It maybe that I'll have to just cut my losses and delete all of them and start over from scratch.