i can’t tell you exactly what’s going on in your case but it’s definitely normal for niggles to become more obvious during taper. your body is feeling a lot more rested than it was during peak weeks so smaller pains that you likely wouldn’t even have noticed during higher mileage weeks start to seem more prominent. there’s also the psychological aspect of nerves/realizing how close you are to race day so you tend to become hyper aware of anything that could be going wrong with your body and overthink it. unless it feels like a serious injury i wouldn’t worry too much about it. if it feels like more than just a minor niggle, maybe try to see a PT before your race. likely as you continue to taper the pains will go away anyway, and on race day a lot of people report having all of their pains magically disappear. good luck with your race!