Act 9 Tunnel Lab help. No exit.

There is no visible exit door in Tunnel lab.

Am I not seeing something?
I did and finished the trials a few times before. Never seen anything like this.
Already reset the map a couple of times but no luck.

Here is the link for larger screenshot:
https://i.imgur.com/NqtPUkz.jpg

Tried the fourth time and found the gate.
It wasn't visible on the map until I get really close, like close enough to actually see it on the screen. Strange. In other labs, the gate is visible on the map from way further away.