If the brake switch is bad, it will trigger limp mode after braking. In my case, it happened right after taking my foot off the brake pedal. That could be happening as you slow down for a turn. There are several threads on here about adjusting the plunger depth by pulling it out a notch or two. You can try that as a free, quick check.
Otherwise, it could be another sensor that’s gotten dirty or broken. I’m thinking wheel speed sensor as a possibility.
2013 Evora IPS - Carbon Gray
2016 BMW 328xi - Estoril Blue