Buggy (?) counting of animals

I'm in year 2 and trying to get the rare animal colors. I was wondering why it worked for some species, but not for others. Turns out the internal counting seems to be buggy.

For example: I have currently 10 ibex individuals (and all color variants). When I look under the discoveries tab it says I have 6 tamed individuals (but if I click on the color variants it correctly shows the number of the individuals with said color - 10 in total). When going to the Breeding Pen, it shows I have 9 ibex.

I have looked at the ibex herd on the 2nd and 16th this spring and both times: no rare. So I think it is because the system thinks I only have 6.

This happens with other animals as well. Has anyone an idea how to get rid of this error?

I will try breeding them and sending some to Grob and also taming new ones, but it will take some time until I can report if this helps. I have also started the game in between a couple of times and I play solo.