Woocommerce Coupons not working

Hello,

So to start things off, I am relatively new to WordPress and woocommerce but I feel like I have a pretty decent understanding of how everything works.

I have set up a woocommerce site and was using the basic pre installed coupon function and had no problems with applying the discount in past orders but when I ran a test earlier today it didn’t apply. It was meant to be a free shipping coupon and originally when I applied the coupon it said it registered it and applied the free shipping but when I went to checkout it charged me for the shipping anyways. This is the first time I have had this problem and a little confused about where to even start or what to try and fix.

Any ideas on what I should even look for to fix the problem?

Thanks,

Alex