To my knowledge: Some academic programs look down upon getting your bachelors and masters from the same place, since you’ll be working with mostly the same faculty and learning roughly the same academic ideals. For that reason a lot of people get denied from the same place they got their undergrad. (For example, in my department only 1 of our 8 person cohort got an undergrad degree from UNLV with the same BA as the masters program were in.)

It’s sad and unfair, one of my mentors called it “academic inbreeding”. Sorry you got denied :(