Lightroom Classic - Create Mask > Select People > All People > Teeth - Bad Mask Issues

When I want to select the teeth of an entire group and I go to > Create Mask > Select People > All People and then select Teeth I get a terrible unusable mask. But if I go in an manually select each person lightroom detects one by one the mask is fine. It would save some time to not hae to manually select each one and just do all, but the all people doesnt make good mask when selecting teeth. Its been that way since day one of this feature and hasn't gotten any better over time. Seems like there is some kind of bug preventing the proper mask to be created when using all people. Is there any reason why this should work this way?

Thanks!