Yeah I experienced a glitch while playing solo.
I was around round 12, I had already hacked excavator for tunnel 6. I let it cut through first then i hacked it but that was like in round 8. So in round 12, after i got back from area 51, I was on my way to the biodome and I went through tunnel 6. I then slowed down because i noticed that it looked like dirt was coming through the ceiling which looked weird.
I went closer to it to look at it and next thing I know I go down. I run back to where the quick revive is to see if the green light is on for the excavator control panel for tunnel 6 but it was off as i figured it would be.
I didn't go through tunnel 6 anymore after that.