Whenever I look up, my mask leaks. The mask is a Hollis M1 and I really like it. The strap is not on tight and when it leaks I'm not wearing a hood or anything that can obstruct the sealing surface. It feels like it's leaking from the top when I'm looking up. I've had the mask for 2yrs. Wanted to ask here first before I go out and buy another one. Thanks.