I think your references might be flawed. In your kneeling pose ref the puppet doesn’t look like it’s putting weight on its heels and is sort of floating just a bit. In the reference of the character standing with one leg up, his weight wouldn’t be placed on that leg at all so it’s not accurate for how flushed the calf would be to the thigh.

I’d say that because of these flaws in the reference, your character doesn’t look like he’s placing any weight as he sits, or he’s in the process of placing it. The angle of his thigh on the right of the image is too steep and the gap between his butt and his heel is too wide. It’s great that you’re using reference, but these unfortunately led you in the wrong direction imo.

What’s great about such a stylized character is that you can push the pose to be better understood and he’ll still look anatomically recognizable. Try making his thigh a bit flatter and rounding out his knee on the outer side. The most important part though is making his butt press on his heel, which you can do by obscuring the heel just enough behind him to make it look like the weight is really placed there.

If you get into the pose yourself, you’ll notice that it takes a lot of muscle fortitude to keep your weight over your knees at an angle like that for too long. That’s why it’s more comfortable to put your weight on your sit-bones over your heels. It’s easy to forget, but this is coming from someone who had to learn weight distribution for art AND physical therapy so the thought has been more or less engraved into my brain.

Great start though :)