Hold your lips together and hang your chin down while keeping your lips closed

I am discovering my problem with multiple masks has been that my chin collapses and kind of hands down and open. Full face masks tend to still leak. I saw on here you can use a cervical collar and I tried that before but will try again. The issue isn’t that my mouth hangs open it’s that my chin fall...

Hello I have both the airfit f20 and f30 mask and they ride up on my chin no matter how tight they are and once that happens they leak from the bottom. The f20 sometimes leaks from the sides.

I am going to try a new mask. What do you suggest? I am a mouth breather. Thanks!