Auto altitude is different from Manual and RTL?

Hello everyone. I currently have three flight modes programmed, Manual, RTL and Auto. On my first flight after selecting the Auto mode, the plane peaked towards the ground at an angle of approximately 90º. I have noticed that on ground the altitude indicated by the Primary Flight Display is, for example, 18 meters in both Manual and RTL (The current height of the plane), however, turning to Auto mode the altitude shown is 380 meters! My question is how can I make my three heights, Manual, RTL and Auto show the same? Thank you !!!

( Flight plan was created with 8 points around the field, the programed altitude was 50 meters when it happens, I took off in manual and selected start mission )