I know that this post is quite old but I seem to have the same problem in 2019. Reading through the posts in this thread I can confirm that you need to operate the levers in a set way to skip the game from bugging out. Looking through the game files I've also found another simpler way to skip this.

So, for anyone still having issues with this bug, I'll write a quick walkthrough for each of the two methods found.

1) The workaround - Pushing levers in a set sequence

This took a bit of trial and error but I found that that you need to push the levers in the following order:
1. Lv31Lever1
2. Lv31Lever3
3. Lv31Lever5
4. Lv31Lever4
5. Lv31Lever2

These are the in-game lever names. You can find these names using the get (or use, but that will also trigger the lever) option of your controller. Just stand near a lever, face it and press get. A message will appear mentioning the lever's name.

If you don't have a gamepad or don't play this game this way, you can also find the lever names by using the debug mode. To do this, press ENTER, type "debug", press ENTER again and finally press F12. In the debug mode, just click on the lever, and it's name will be shown in the left part of the screen. Exiting debug mode is done by pressing the ESC button.

Because checking in-game names isn't quite intuitive here's a quick walkthrough of the order you need to push these levers:
1. From the starting position (where the roads split in 3 directions), go left and then south. At the end of the flaming corridor, press the first lever (Lv31Lever1).
2. Backtrack your way just before heading south and continue going left and up. Ignore the left opening (guarder by zombies) for now. That would be the final lever. Instead go up and a bit to the right. When you see a opening to the north just follow it. At the end of the waterfall path you will find the second lever (Lv31Lever3).
3. The third lever is at the bottom-right side of the starting position. You can backtrack all the way from the previous point or just go to the right and down, but ignore the lake portion to the right. This is just a small section with the third lever (Lv31Lever5) in the center.
4. Backtrack from the previous lever and go up and right, towards the lake. At the end of the green corridor you will find the forth lever (Lv31Lever4).
5. The final lever, as stated earlier is on the left side of the starting point, between points 1 and 2, in a small niche, guarder by a zombie.

2) Unlocking the doors yourself - Using debug commands
There are multiple ways to do this, using the debug screen but I'll just list the ones that I tried myself.

Do note that if you are doing this, you should stop using the levers manually otherwise the game may bug out.

First things first: go to the corridor with the 5 gates and open up the debug screen. To do so, press ENTER, type "debug", press ENTER again and finally press F12.

From here you can do certain actions like:
1. moving or removing the gates
2. unlocking and opening the gates

1. To move the gate just select it with the mouse cursor and drag it around. To remove it click on the gate and press the "DELETE" button on your keyboard.

2. The game's files mentions two events: unlocking the gate and toggling the opening animation. From what I've tested, unlocking isn't necessary, but you cannot trigger the opening animation as Locke as it will reset after teleporting you before the gate.

To unlock the door (optional) type the following command in the debug console: Lv31Gate1.stat LOCKED=0. This will unlock the door.

To trigger the opening animation without looping, type the following command in the debug console: Lv31Gate1.state "opening". This will open the gate and leave it open.

The gates are numbered from 1 to 5, so just replace the last digit to whatever door you are stuck at. Possible values are: Lv31Gate1, Lv31Gate2, Lv31Gate3, Lv31Gate4 and Lv31Gate5.

It seems that you can also skip the name part if you have the gate selected in the debugger.

Exiting debug mode is done by pressing the ESC button.

Hopefully this quick guide will help anyone else stuck at this portion of the game.