Bose ProFlight users: how often do you change ear tips?

I fly 737 with the Bose ProFlight 2 headset that use the Bose QuietComfort StayHear+ tips. The medium tip fits best but I notice after a month of use (about 80 hours) it seems when I tilt my head side to side or look up or down the "seal" of the tip in my ear breaks and lets in outside noise. A tiny bit of physical pressure to the side of the tip and it reseals but it is becoming necessary more and more often. Is this the tip wearing out? How frequently do you change yours out normally or do you? I ask because my only experience with "in ear" earbuds other than my ProFlights are my Beats Fit Pro with a similar design and they seal as well with nearly 2 years of use as the day I bought them, while the StayHear+ Bose tips are really finicky (large: seal always breaks after a few minutes, medium: worked fairly well for a few weeks now is breaking the seal more and more often, small: no seal at all.) The curved ear hook fits perfectly in my ear ridge so no issue there. Thanks!