Old account not working right - unable to complete campaign

I had a few characters at level 50 before D4 expanded things to level 70. I started playing again to check out all the new updates and I can’t increase the difficulty without completing the campaign. I can’t complete the campaign because the quests aren’t available. I’ve already completed the campaign so I don’t understand why it’s not working. My rogue and barbarian characters had all their gear still but I had to reset their skill tree and get to level 70 to reset their Paragon. But now I can’t increase difficulty… I think it’s bugged from all the updates and seasons and things D4 added since I last played. I had about 250 hours of gameplay in these characters so I’m not interested in just starting new characters. Can anyone fix this so I can keep playing on these characters?