I had a similar problem when I aligned the highback with the board, as it should be. The cable was not symmetric anymore and would pop out of the guide. Reduce the angle of the highback respect to the edge of the board until the cable stays put.
Another possibility is that the right side guide in your pic moved a bit, check that the screw is tightened and not moving. I see your right side cable attachment a bit high, there is a screw at the base of the ankle strap, make sure it is tight enough so that the cable attachment cannot rotate too much and go out of place.
Tighten the screws regulating the angle of the highback ( left and right, under the ankle straps attachments) make sure they are not loose letting the binding unaligned. They do loosen up.
There two small "bumps" for lack of a better term inside that piece that keep your cable aligned, forcing the cable to stay inside. Make sure that the cable is placed correctly in the first place. I am trying to replicate your issue on my binding...unsuccessfully.
Hope this helps!
Thanks Kirkrider, ive tightened everything up and will try to get out this weekend and test it again.
i ride a pretty square stance, so I didnt need to realign the highback with the heel edge of the board. It's still at its factory setting.
the two small bumps are also still in the channel, and are not showing any signs that they are worn.
It's odd because at home I can't get it to pop out as regular as when i'm on the hill.
i'll let you know how it goes.
thanks for your help