Game Breaking Bug in FFXV Chapter 14 Insomnia?

[bltz!]

So I started my 2nd playthrough, and I just entered Insomnia. Here's what happened:

1. Progress through the map, go into first underground tunnel
2. Fight soldiers and mechs, go 1 floor lower
3. Find dead Glaives, fought Black Flans
4. Go up the stairs to have a cutscene with Cor and he joins the party to fight Ahrimans
5. Go to Glaive base, start some sidequests
6. Go out to the main map of insomnia, go into 1 of the underground campsites and save
7. When I load my next save, I'M BACK AT THE BEGINNING OF INSOMNIA
8. My sidequests are still there
9. When I go through steps 1-4 again, the soldiers and mechs in step 2 are gone, the game still highlights the dead glaives and the Black Flans are still there, and the game blacks out when the cutscene with Cor is supposed to start
10. Music is still playing, I can still hear the characters making sounds like "Hmm", and I can still pause

I can't end the game. Anyone experienced this, and found a solution?

I did a level 1 run, trying to do a perfect game, so I've already done all sidequests and treasures. That's 70+ hours of my life I'm not getting back.

[Chere]

I had this bug on old version of the game. Do you play latest version?

[bltz!]

I just updated to the latest version (with Ardyn DLC all included), but still same problem.

Did you manage to find a solution?

[Chere]

Do you have a save file right before going to Insomnia? Load it, might help. Worked for me

[bltz!]

Unfortunately I don't have a save before Insomnia, which is where I screwed up

[Mist]

Known to happen with an illegal version in the latest patch. Too bad uh, maybe buy the game next time.