I found that if I use sqrt or power 0.5 in acados_python with casadi it produces nan

I test race_cars in the acados_python example,“f_expl = vertcat(
v * sin(alpha + C1 * delta),
v * C2 * delta - kapparef_s(s) * sdota,
Fxd / m * cos(C1 * delta),
)”,i change the v to casadi.sqrt(v),the solution failed.And it happened in my own example,I’m guessing this happens in every case,not just in my model. And when I tested it with print_level turned on, I noticed that the BAbt matrix appears nan when I use sqrt (a declared MX variable), and if I replace sqrt with power (a declared MX variable,0.5) it also appears, whereas power(,2.3) doesn’t, and anytime it’s 0 to 1, it’s nan