To create subscriptions with cycle detection enabled, add the transactional subscription to the databases.
EXEC sp_addsubscription @publication = N'two_way_pub_test1', 
    @article = N'all', @subscriber = N'CHRISMOF1', 
    @destination_db = N'test2', @sync_type = N'none', 
    @status = N'subscribed', @update_mode = N'read only', 
    @loopback_detection = 'true'
GO
  
EXEC sp_addsubscription @publication = N'two_way_pub_test2', 
    @article = N'all', @subscriber = N'CHRISMOF1', 
    @destination_db = N'test1', @sync_type = N'none', 
    @status = N'subscribed', @update_mode = N'read only', 
    @loopback_detection = 'true'
GO