PhiNotPi, the rules are correct.
Here is what is happening:
1.) The alga is not allowed to make its own chloroplasts.
2.) When the robots load in the total chloroplasts are (5000 * 5) = 25000 --> 25000 / 16000 which is about 2 'avg' chloroplasts
3.) The system keeps repopulating until the 'repopulation threshold avg vegys' is above 10 (as defined by your settings)
The key point here is that 'average vegys' does not actually mean 'population' anymore. It means the amount of chloroplasts on the screen.
The only thing I can think of doing is choosing better names for these settings:
Rates for Average Repopulation
Maximum number avg. vegys.
Repopulation threshold average vegys.
It is a little confusing for new users to understand that we are dealing with chloroplasts here, not actual population.