3 digit locks only take a few minutes of going through the combinations to unlock it.
So it's possible another player just tried different codes and changed it to their own code after they got in.

If you just try all possible combinations you can let yourself out of the base again :)
I'm always starting with the 500 ones and then go up from there. Most of the times it just takes 5-10 minutes to unlock a random 3d digit code

Exact same thing happens with the 4 dial locks. It's not the code changing, it's the lock simply not falling off. It's happened to me numerous times (even as I type). I've been forced to destroy my own gate and when the lock drops, I pick it up and look at the combination...the exact combination I input into the lock. Putting the same lock back on will cause it to happen again. Putting a new lock on will fix it...till that one also bugs out and you have to destroy your gate again.

In T154627#2120178, @ProfessionalDead wrote:

3 digit locks only take a few minutes of going through the combinations to unlock it.
So it's possible another player just tried different codes and changed it to their own code after they got in.

If you just try all possible combinations you can let yourself out of the base again :)
I'm always starting with the 500 ones and then go up from there. Most of the times it just takes 5-10 minutes to unlock a random 3d digit code

There are a total of 1000 possible combinations on a 3 dial lock...I find it HIGHLY unlikely you can crack the code in 5-10 minutes.