All That Glisters - FAILED

So at some point of the game I started doing side quests. Completed a couple of DLCs. 20+ hrs of gameplay in (after I gave up the main quest. I have 56hrs overall) I find out that the main quest is bugged.

It’s failed failed. It seems, according to the journal, that it stopped after I’d spoken to Florian and went to the Custodian’s cellar. Nothing more.

I tried fixing it. Re-installed the game. I found the counterfeiter’s camp and defeated the baron. Then they told me to have a rest and talk to Sir Radzig.

I thought, that that was it. But the quest was still failed, but it had an objective to talk to Sir Radzig. But whenever I came up to him, the screen went black for a moment and that’s it. No dialogue options as well.

PS I can’t talk about the quest to any of the character (eg Zach, Rapota etc.)

Is there a way to restart the quest or “bring it out” of the failed quests so it’s active again?