A couple times now when defeating a Monolith boss/Harbringer, during the Activate Blessing menu my current blessing is listed as Undiscovered, and doesn’t show the bonus from it. When I go into the Blessings window in Inventory, it lists Undiscovered there as well.
After selecting Keep Current, it still lists and Undiscovered in Active Blessings.
The following link should have a screenshot showing each of the above.