hmmm try this test to see if the respirator is sitting correctly on ur face lol
1. put on the respirator
2. exhale test- place the palm of your hand over the circle thing in the front, and exhale. if the seal is properly closed around ur mouth and face, the respirator would start to start to make u feel a slight pressure build up
you might have a faulty respirator if no other explanation is reached. i would try and figure out what could be wrong before you begin to work again
good luck