Unfortunately this effect is widespread and appears to actually be caused by the vaccine. Anecdotally of our friends who got the shot they complained last year of being sick two, three even four times whilst I got omi once and my gf never. One friend even stated specifically that it was only the vaccinated people in her group where that was happening.
The shots trained the immune system against the obsolete 2019 version of the spike protein, but our bodies can't tell the difference between the mutated versions and the original. They spot a SARS-CoV-2 spike and start making the same antibodies they were trained to, but those antibodies aren't fully effective because of the mutations. And unfortunately the body doesn't seem to be able to 'unlearn' this because people keep taking boosters, and/or it may be incapable of unlearning anyway even without boosters. It's a bit unclear.
The problem can be seen most clearly in UK government data because they were willing to show data on case rates by vaccine status pre-adjustment, which by the time they stopped publishing the data showed 3x-4x higher rate of COVID infections in the vaccinated cohort and still getting worse. That's why even the headline rates (subject to much invalid data game playing) showed effectiveness start at 95% and fall rapidly as the months went by.
Such problems have happened before, pre COVID. Fauci even noted in an interview that this can happen, safety testing is meant to detect it but the process was so accelerated there was much less time to see it than normal.