If two experience entries are really the same job — for example, after importing more than one resume — use this to combine them into a new, single entry. You'll see both experiences' bullets side by side and click the ones you want to move over, in the order you want; nothing is chosen automatically. Merging creates a brand-new experience with just the bullets you selected — moved, not copied, so a source experience you select bullets from ends up without them. The two original entries themselves aren't deleted, but any bullets you moved out of them are gone from them; review the new card, then delete the originals yourself once you're happy with it.
Any bullet you move over keeps whatever skill links and approval status it already had — you won't need to re-approve skills for anything you didn't change.
Still stuck? Report a bug or request a feature.