Failed to save rally point

I’m trying to set a Rally point but when I select Upload i receive after some seconds the message “Failed to save rally point” .

I’m new to this procedure , is it possible to set just one rally point ?

Rally_Total parameter is update with the corresponding number of Rally Points set

I’m able to write and read waypoints but not to upload rally points

I found out that rally pints are permanently stored in the Eeprom.
So the problem might be related to the flight controller , Pixracer in my case rather than Mission Planner ?

I have test Rally points with a Pixhawk clone at it works so the problem is related to Pixracer