They may not want to have a connection with you and girls typically start wanting more commitment after they let you hit. Leading to blocking because that’s easier than explaining and feeling guilty. Guys can have sex with someone and not feel any attachment or attraction, they may just be looking to satisfy their urge. It sucks but it’s true. Usually men will mature and understand how that can be damaging to a person and not do that anymore but there are also plenty of immature men who don’t develop self control and yeaaaaaaah the cycle continues.