Same issue here, someone has been using my (newly issued) USPSA member number (A156365) for a few years now- their matches are visible on my PractiScore profile: https://www.practiscore.com/profile/chris-van
I opened a thread here asking if this is going to have a negative impact on me over time or if it is simply irrelevant… https://community.practiscore.com/t/someone-using-my-uspsa-member-number/12672