I reported this bug a while ago, it was fixed in 2021.1.1-beta-3. It was caused by a division by dt (the time difference) between initialize() and execute() which was 0 when sim time was stopped. It was fixed. What WPILib version are you using?
Copied the command, seems like the NaN values are coming from the PID Command. After removing them, the robot seems to move, but not accurately (expected). We had this same problem when testing vision tracking.
Is this with simulation-stepped timing, or on a real robot? And when you say that the NaNs are coming from the PIDCommand, do you mean from the new command-based PIDCommand or the PIDControllers inside the RamseteCommand?
After upgrading, does the RamseteCommand still output NaNs?
NaNs, Infinity, and -Infinity occur when dividing by zero with doubles. I’ve gone over the PIDController code, it seems that the only div-by-0 possible is if period = 0. Make sure that you aren’t passing 0 as the fourth parameter to the PIDController constructor.