It is minor but it was beginning to get annoying. My body weight has been up and down so I was beginning to wonder if my mask was properly fit when I was heavier. So glad it was a minor issue because I really like that mask.dare i say it....dont look up. lol in all seriousness, i had a neck seal that always let water in when i looked up. i had to be very careful and learned to move my body instead.
but in your case, many times when we look up we wrinkle our forehead by squinting or lifting our eye brows.
i wouldnt toss out a mask i really liked just because of this. it is a minor issue