Huh?
The First Amendment protects freedom of religion. One aspect of that is that religious institutions have the freedom to choose which sexual deviants are not allowed on the team. Hence said exception to Title IX supports the First Amendment.
Want to know what is not Constitutional?
Title IX.
The Constitution does not allow the federal government to fund educational activities. Thomas Jefferson recognized this in his Sixth State of the Union address and specifically petitioned Congress to Amend the Constitution to allow federal education spending. No such amendment was ever passed by the Congress, nor was any such amendment ever ratified.
So just eliminate Title Icks.