It is amazing how my wife, who leads a women’s bible study group in our church has bought every Christian book used from Amazon for her classes.
Then, the other women pay her for their books after they are received distributed at the next meeting.
I attended a mixed group bible study a couple of years ago, and I ordered the books for our class and did the same as my wife does.
I would suggest you switch to christianbook.com or some other Distributor of Christian books. Amazon is not a friend to Christians.
I’m not sure how selective they are in their bans. A friend of mine is a Christian author. His newest book has been banned by Amazon.