I struggled with this for a long time and seems that the info saved with SAVE_CONFIG had formatting issues that stopped mine from working.
Using the Klipper configuration tools produced output like the following:
#*# <---------------------- SAVE_CONFIG ---------------------->
#*# DO NOT EDIT THIS BLOCK OR BELOW. The contents are auto-generated.
#*#
#*# [extruder]
#*# control = pid
#*# pid_kp = 33.186
#*# pid_ki = 4.609
#*# pid_kd = 59.737
#*#
#*# [heater_bed]
#*# pid_kp = 64.270
#*# pid_ki = 0.758
#*# pid_kd = 1361.723
#*# <---------------------- SAVE_CONFIG ---------------------->
#*# DO NOT EDIT THIS BLOCK OR BELOW. The contents are auto-generated.
#*#
#*# [probe_eddy_current btt_eddy]
#*# reg_drive_current = 15
#*# <---------------------- SAVE_CONFIG ---------------------->
#*# DO NOT EDIT THIS BLOCK OR BELOW. The contents are auto-generated.
#*#
#*# [temperature_probe btt_eddy]
#*# calibration_temp = 34.966247
#*#
#*# [probe_eddy_current btt_eddy]
#*# calibrate =
#*# 0.050000:3245727.450,0.090000:3245473.506,0.130000:3245054.849,
#*# 0.170000:3244668.773,0.210000:3244207.433,0.250000:3243794.898,
#*# 0.290000:3243352.162,0.330000:3242917.546,0.370000:3242479.500,
#*# 0.410000:3242040.906,0.450000:3241604.228,0.490000:3241185.592,
I manually changed it to this
#*# <---------------------- SAVE_CONFIG ---------------------->
#*# DO NOT EDIT THIS BLOCK OR BELOW. The contents are auto-generated.
#*#
#*# [extruder]
#*# control = pid
#*# pid_kp = 33.186
#*# pid_ki = 4.609
#*# pid_kd = 59.737
#*#
#*# [heater_bed]
#*# pid_kp = 64.270
#*# pid_ki = 0.758
#*# pid_kd = 1361.723
#*#
#*# [temperature_probe btt_eddy]
#*# calibration_temp = 34.966247
#*#
#*# [probe_eddy_current btt_eddy]
#*# calibrate =
#*# 0.050000:3245727.450,0.090000:3245473.506,0.130000:3245054.849,
#*# 0.170000:3244668.773,0.210000:3244207.433,0.250000:3243794.898,
#*# 0.290000:3243352.162,0.330000:3242917.546,0.370000:3242479.500,
#*# 0.410000:3242040.906,0.450000:3241604.228,0.490000:3241185.592,
#*# 0.530000:3240798.984,0.570000:3240451.332,0.610000:3240033.308,
#*# 0.650000:3239688.771,0.690000:3239305.816,0.730000:3238933.830,
After these changes it started working OK