So there's a few things wrong in my current save, first of all Zixzax seems to be bugged, he doesn't open nor introduce any new portals at homestead even after finding more star stones and popping some bloodstones and thus the gate at the Source Temple also refuses to open. I've counted now 12 inert stones, stacked in the middle of the first town, in addition I have the 5 bloodstones in my inventory (reloaded after trying to pop them to avail), yet the imp refuses to do anything. He was stuck saying "Well, aren't you going to jump through?" with the skillpoint-reset-demon, we went through the portal many times but he still kept repeating that same line... Until we *tried* to kill him. This let us speak to him and open his dialoque options again but he doesn't leave that one spot anymore, seemingly doesn't open new conversation options nor anything else. I guess this is due to us accidentally glitching into the same demon room earlier (player sits/sleeps while teleporting to homestead) which triggered a flag with him causing him to be stuck and not able to open new portals anymore, or something. This is literally gamebreaking and blocks advancement.
The second one is the same one someone here already mentioned, the secrets vendor not selling the abilitypoint books after purchasing them only once. No resets on level-up, time-based nor game reset.
Then there's the "same stuff not stacking for some reason", i.e. I have two small stacks of arrow shafts that just won't combine. Nothing big but just throwing that out there.
I'll post the save and analysis results if requested but if you've got some insight on a similar issue in the past that might help, I'd like to hear of a possible workaround or fix to get Zixzax to open up the portals he's supposed to so we can advance as per usual.