Thank you for your previous comment too, I read it, it was very thorough!
This is just the first plasticine I found on Amazon.
Also, this time I didn’t follow the usual proportions measuring that I try to start off with. I saw a TikTok of somebody making a polymer clay head and they went for facial features straight away, without building the skull at all, and so I thought what the heck, let’s do it. I don’t know if it’s noticeable / causing more issues compared to the last time?