Known Issue: Legendary Artifact Combining
A bug in the artifact combination UI was recently brought to our attention. We wanted to post here to make everyone aware while we work on a permanent fix.
When you're in the artifact combination UI, clicking on the autoselect function will normally fill all empty slots with an artifact of the appropriate rarity. Unfortunately, there is currently a bug in the UI that makes it so that, when clicking the auto select option for Legendary Artifacts, it will select FIVE legendary artifacts instead of the intended TWO. Here's an image to demonstrate
Even though the Legendary autoselect should have only chosen two, it has selected - and will consume - five artifacts.
Make sure to double check how many Artifacts you have selected in your inventory before combining until we have a permanent fix!