It is probably not that unusual, since many AP exams have fairly low score distributions, as shown at https://secure-media.collegeboard.org/digitalServices/pdf/research/2019/Student-Score-Distributions-2019.pdf .
Indeed, one large school district posts an AP report at https://www.houstonisd.org/site/handlers/filedownload.ashx?moduleinstanceid=73138&dataid=264353&FileName=AP%20Report%202019%20final.pdf . Figure 7B on page 18 shows what AP scores students with various course grades earned. For arts, history / social science, and science, the modal score for A students was 1, and for English, the tied modal scores were 1 and 2.
So it is not too surprising that there are high schools where the AP course content and grading standards fall far short of what the AP exams test. A reasonable expectation is that a well taught high school AP course should have A students earning 4 and 5 scores, but many high schools’ AP courses fall far short of that.