Problem to fix ESC

Hi, I’ve tried to set up my ESC and it worked but I don’t know why I have to do it every time I turn on my copter. I have an APM 2.8 and the ESC are simonk 30A. Another problem that I found, it is than not all my motors start to spin at the same time and they no have the same revs. How can I set them?
Thanks a lot!!

Have you done a calibration of all the ESCs involved?

Hi, thanks a lot! It’s done, the problem was the RF that was broken. I’ve repaired it and now everything works perfect!