Ranger – “Defense” [Campaign 5, Mission 3]

Do you already have a checkmark next to the quest to free Talannar and Dirael?

No, I don't. Although they are already freed!

Here's how the game progresses:
I capture Cyris-Talu, spend a week gathering strength, and defend. Then I buy a hero there, and with Faidaen, I go through the right pier (where the elves are) to the "M..." castle - I capture it, level up for another couple of weeks - there are quite strong garrisons ahead... Along the way, I gather a garrison - and the checkmark appears. And then I go for Talannar - I free him... on the way, I also beat up the blue one. I go through the factory to the Necromancer castle - since I have a summon, I fill it with units from the "M..." city - I defeat the necromancer, go to the Dungeon - I free Dirael....
And then... SILENCE...
I bought another hero in the Necromancer castle (an elven one, though), and no one recalculated anything!
And this CHECKMARK still hasn't appeared...
I've been playing like this for a year now... (in game time, of course))))
I replayed this mission as advised here - NOTHING.