The Tale of Igor's Campaign

Went past the outpost, destroyed the first castle to the right of the dragon utopia, climbed to the top, destroyed the second castle – a cutscene about completing the campaign and the looting quest appeared. Since I didn't hire half of the troops in my castle (didn't have enough money), I reloaded before the battle, went through the dungeon, destroyed that castle – again, a cutscene appeared indicating that the quest was completed. I reloaded again, ran around all the available territories, reached level 31, and got the skills "Pure Rage," "Sharp Mind," and "Distraction." I gathered all the troops from Lag-Didak, destroyed the second city – no cutscene. Destroyed the third – no cutscene. Destroyed the last one – no cutscene, the quest wasn't registered, and I can't go past the outpost. I'm scratching my head, wondering what happened. There are no mods, and I deleted all additional maps before starting this map.