Quest starts on a board near a tavern in Novigrad. You battle Vivaldi and he tells you to got battle that hostess in Passiflora. After you battle her she sends you to a "Sigi Reuven". But instead of updating the quest it completes. I looked into the guide and it said that you should battle Sigi and then someone else for a rare Gwent card.. Well this is not possible...

Please fix it..

I ran into this problem too. I was just doing the Gwent rounds cause I wanted more cards to build an elf deck. I got to the madam and I encountered that problem where it didn't give me the location of the next Gwent player.

Gwent isn't very well constructed. I only have a Temeria/North deck cause all the cards I have gained are of that branch. I would really like to play the Monster deck or Squirrel deck but lack the cards to build a deck of them. Why isn't there a vendor dedicated to selling Gwent cards in the Witcher world?

Having the same issue

Good news for everyone, just keep playing Witcher 3 and you will eventually meet Sigi Reuven, you can't miss him. Once you meet him you can play vs him, then the Quest will be active again!

This quest is buggy...but I'm having a different problem--I can't play the Madame of the Passiflora. She just stands there, and there's no way for me to interact with her.

Now, I did have problems with the Dijkstra quest in the Passiflora as well--the Madame just stood there instead of leading me to Sigi, et al in the back of the Passiflora, so I imagine it has something to do with that being janky as well?

Regardless, I can't play Gwent with the Madame...so any suggestions would be welcome.

I feel your pain on the Serenity not moving. To do the dijkstra quest. Walk into the room behind you if facing her > turn right into the next room > walk over to the tub > If all else fails just search this forum its how I found it out.

Still haven't found a way to play her. If you win the high rollers match can you still play her or will it fail the mission like a few quests have?

Actually haven't tried the High Rollers quest yet--didn't have a good enough deck, from what I gathered.

I'll try that and see if that fixes things and report back.

Same bug. I did not do the assassination of Radovid quest, as i did not want to take part in such a scheme. And it seems I can't talk to Serenity now.