EE 2.11.8 broke CartThrob 2.71

After updating ExpressionEngine from 2.11.7 to 2.11.8, CartThrob 2.71’s order items stopped recording numeric information such as the order item’s price, subtotal, quantity, etc.

I did not make any other changes when updating EE, and when I rolled back EE to 2.11.7, CartThrob resumed working as it should.

Has anyone else experienced this issue? Is there a fix?

(PHP 5.5)