For the last science mission you need to have 100% genome completion for a number of dinosaurs and a Pentaceratops. I can only get to 92% and it says it's excavation site says 'completed' not 'depleted' so I can't finish the mission even if I tried
If, for some reason, multiple sites show completed, it's a bug. They will never show depleted (let alone completed) until unless you unlocked 100% genome.
I vaguely remember reading a workaround. I think it was 'go to the next island and put down an expedition center' but don't quote me on that, I didn't run into this bug myself.
EDIT: No wait, it's Sorna. Do you have Expedition Centers active on each preceding island?