Did you enter the last opened area, get a conversation with Astarte or the demon, and return to the main section of the homestead through the portal?
No, I'm nowhere near the last areas of the game, if that's what you mean (just entered the Phantom Forest, in-story). As for other areas, I've had a conversation with the green lady in the Hall of Heroes, the personal rooms of the Hunters' were empty, and I've unlocked the Fire Elemental room and talked to the fire merchant there. I am not sure I have returned back to the main hall through the portal from
each room, but from the most of them, likely.
Was Zixzax at the start of the homestead, by the statues, by a portal or the weaver? Did he have his regular dialogue options or was he urging you to 'leap through'?
If he was by a portal or near the start, approaching an inactive portal can trigger a dialogue with Zixzax and open the portal. If he was near the statue, you may be able to click on it to proceed, if Zixzax doesn't react to your approach.
I will try it out after dealing with the attack. Zixzax is mostly hanging around the Weaver of Time whenever I visit the homestead.
If the problem is with Zixzax, killing him can reset his status, and get him opening portals again. That is feasible starting about level 12 or 13, depending on your party build.
I take it he will revive, but won't that make him permanently hostile??