Mirror Walking not using Concentration skill

[Styrbjorn]

From Wiki "Instead of Search Skill as bonus to your DC check you can use your Concentration Skill if higher at a -4 value. "

Alistair has 1 search and 25 concentration.

From Event log:
[Notice] You have teleported to this destination 2 times.
[Notice] <color=#C972EC>Teleport Roll : success : (19 + 2 = 21 vs. DC: 6)</color>
[Notice] You were attacked by a solitary mirror image during your journey!

[Styrbjorn]

This must be an incredibly stupid question, even for me. At least tell me, please, what I have misunderstood.

[EasternCheesE]

Hello there.
I have a suspicion why it happens as it happens. I got few questions related to your PC to further investigate, please check your PM.

[Styrbjorn]

This is an example of a failure.

[Notice] You have teleported to this destination once before.
[Notice] <color=#C972EC>Teleport Roll : success : (12 + 3 = 15 vs. DC: 10)</color>
[Notice] You are thrown off course!
[Notice] You were attacked by a solitary mirror image during your journey!
And 18 hp damage as a bonus.

And a success. From the same location to the same destination.

[Notice] You have teleported to this destination once before.
[Notice] <color=#C972EC>Teleport Roll : success : (17 + 3 = 20 vs. DC: 2)</color>
[Notice] During your journey you come across tracks indicating a pack predators are nearby, you manage to avoid them.