If true, it would seem to me that law is very questionable under First Amendment grounds. Is there a constitutional issue here?
You would sure think so. First - it’s a religious organization asking. That seems to be right in the thick of the First Amendment. Then we can move over to “free speech” as an afterthought. Here is an organization that says “Our religious beliefs agree with this organizations goal. We want to encourage it by donating money to them.”
Seems to be an unconstitutional limit to me!