Have WooCommerce Subscriptions but am having problems

I have set up a couple of products using WooCommerce Subscriptions and when I add these products to the shopping cart, they work fine. However, if I add these same subscription products to a component in WooCommerce Composite products extension, the extension seems not able to recognize these products. It does for all other products however, just not subscription products. Is this normal? Does anybody have any suggestions as to how I can get Composite Products to recognize subscription products? Thanks