Need help! Auto-translated

I have the gold edition of Heroes of Might and Magic III. I've completed the first three campaigns from The Restoration of Erathia, but the new ones haven't unlocked! Also, I noticed that when I complete a campaign, a checkmark appears, but as soon as I exit to the menu, the checkmark disappears! Can anyone help? I really want to complete all the campaigns:smile05:

when you complete a chapter of a campaign, SAVE, and when the last scenario is completed, load the last save. Just don't give the same names and don't overwrite the same name. I suggest labeling each mission with the name of that mission, for example, Black Sheep.CM1, and continue. And when the scenarios are finished, click LOAD, not new campaign.

Yes, after completing each scenario, the game offers to save the progress for a reason! The save file records information about what you have already completed, and based on this, the next, previously unavailable campaigns are unlocked. Otherwise, you would have to start from the very beginning.