There are different credit scores, and each has its own secret formula. Based on this page from USAA, I believe that the credit score you are seeing through USAA is VantageScore 3.0. This is different from the more famous FICO score (which is used by most lenders) in a number of ways. One key difference between the two is how recent credit inquiries affect your score.
According to credit.com, deduplication is different between the two. When you are shopping around for a mortgage or car loan, you may have multiple credit inquiries in a short amount of time. Deduplication is the process by which the credit score detects this activity and considers it all one inquiry. The article claims that FICO uses a 45-day window for deduplication, but VantageScore only uses a 15-day window.
Credit inquiries remain on your credit report for 2 years, but according to this article on Experian.com, credit inquiries only affect your FICO score for a maximum of 1 year. I haven’t found any articles that report the length of time that inquiries affect your VantageScore.