I'm currently playing a sandbox game as the Korath.  Its version 2.2 (live) with the "Tales from Centauron" DLC instlalled

So I''m playing a sandbox game with the DLC installed and playing as the Korath. I conquered a Drengin core word with a spore ship, after it was conquered it reverted to a colony, the spore ship was consumed during the invasion (as expected). A few turns later I assigned a govenor, I then noticed that the planet population contained my Korath solfier that was aboard the spore ship and all the Drengin citizens, I thought the Drengin should have been killed during the invasion? Unfortunately I dont have a pre invasion save as I didnt notice the issue untill after I made it a core world again. I have a "pre installing gov" save and a "post installing gov" save which I will provide in a link below. The name of the planet is Sina 2

Later I conquered the Drengin homeworld with another sporeship. Again the planet was instantly conquered consuming the ship in the process (as expected. I made a save before the invasion called "pre spore" and made a save after the invasion called "post spore". After the invasion I noticed the pop of the colony was showing as 10. I removed the governor from Sina 2 and assigned them to Drengi. When I opened the core world management screen I noticed that there was 1 pop (my Korath soldier which is what I expected to see. However about 6 turns later I noticed that all of a sudden the pop on Drengi was 7/9 with 5 of the seven bieng Drengin (I'm not sure how this happened I would have though only Korath pops would have spawned) also for some reason the world management screen is saying I'm loosing pops due to overcrowding which does not make sense. I've made save called Korath turn 112 for this.

https://1drv.ms/f/s!AmyMgP8uhBKuhnbBC5RDjObH4OTB?e=zocDEa