Combat Inspiration is a Class Feature available to College of Valours. This ability is an enhanced version of Bardic Inspiration that adds the ability to increase the target's armour class and damage.
See also: Bardic Inspiration, the base ability available to non-Valour Bards
When the recipient of Combat Inspiration expends the granted Bardic Inspiration Charge on Valiant Damage or Valiant Defense, the buff will not get removed. This leaves a non-functional, lingering buff that prevents Combat Inspiration from being reapplied until it is somehow removed.
A workaround to this is to use Valiant Roll which will correctly remove Combat Inspiration. This works even after you have expended the Bardic Inspiration Charge. The most readily accessible way to do this is to enable Valiant Roll and Shove anything.
This bug only occurs with the upgraded +1d8 and +1d10 variants of Combat Inspiration. The base version works correctly.
On the other hand, this bug can work in your favor. If you apply Combat Inspiration to another Bard, the recipient can continue to use Valiant Damage on each attack without having to reapply the buff until they run out of Bardic Inspiration Charges.