Discount displayed but not applied

We have an 'applies to all purchases' discount that has just one condition - that another subscription is active or is purchased at the same time.

We've set the display to be 'automatic sale display...'.

On the subscriptions tab of the user's profile, the discounted price shows properly (shows a $25 discounted price). [Because the user has the proper/conditional subscription already]

However, after checking the box for the subscription and then clicking the subscribe button, the order is displayed with the full/original price and the user is charged that price - not the discounted price (the discount is not actually applied).

I've reviewed the various settings of the discount but all seem to be working properly. The discount is working fine on the subscription display - but lost when you get to the actually check-out process.

The invoice (in the pop-up after selecting check payment option) does include the discount 'wording' in the 'thank you' area at the bottom (because we inserted the code to include that final payment option.

So displays that use the wording work, but the actual item/order is never actually discounted.

Is there something that I'm missing somewhere?

(We are using the latest 4.1.1 version of CBsubs; however, this was happening prior to that upgrade also)

Remove the condition and see if the discount will apply to any purchase. This will help determine if it's the condition that's failing.

I should have mentioned that I already tried that.
Same results (discount shows on subscription page but not on checkout)

Just so I know that I'm looking in the right place.

An automatic discount should still show as a discount line (a separate line in the checkout, after the total) shouldn't it?
Or should it just show on the individual item line (because the discount is applied to a specific subscription)?

This could be a case of me messing up the display of things with overrides.

It should show under the total like any other promotion being applied. Even if you override the columns display (try setting back to defaults) it should still apply. Ensure CBSubs Promotions is public and published within CB > Plugin Management. Aside from that I don't know what to suggest other than carefully review your promotion to ensure it's enabled and accessible (ensure access view level and user group is set to Public under Groups tab).