I even have the damn comments to easily prove it's been active: rule34.xxx/index.php?page=post&s=view&id=911587

Glitch in the site most likely

Is it avoidable?

the real question is how have you been using the site for over ten years

I've been getting cloudflare glitches for a while now, I found reloading the page will eventually load the recaptcha button. Maybe the same will work for you?

By not being a fetus.

Probably because you've barely used it. Hardly any comments or forum posts in 12 years. You probably need to post more to prove your activity