Oh man, that "red mark across my client's forehead" part hits close to home. I mean I had almost the exact same thing happen with one of those flexible LED masks like three weeks ago. The adhesive just gave up halfway through and slid right down her face. It's super frustrating because those masks are supposed to be the gentle upgrade but the straps are total garbage. I ended up just switching back to the old rigid mask with the headband because at least that stays put. idk maybe the flexible design is just too lightweight to hold itself in place for a full session.