How do I make a yell look right?

I’ll try to edit and add example photos later, but I’m not able to rn.

Anyways, the problem I’m having is that whenever I’m trying to make a character’s expression that of an enraged yell or something along those lines it looks… wrong. Like a yawn or someone just passively holding their mouth open. Is this a common problem for beginners? Or am I missing something? Or am I just looking too hard at it? Is it possible that everyone else has the same problem and it’s an issue with the medium? Any help would be appreciated! :)

Also, as an aside, I said I’m a beginner but I have been playing with Heroforge for years atp and even use pro. I say beginner because that’s my proficiency level lol. Very novice