PM07 burned

Hello, I’m new at RC. That was my first octocopter. I have Pixhawk 4, PM07, HGLRC 60A Opto, 22000mah 6cell 488.4Whh battery. Yesterday I was trying to connect esc to the PM07. I soldered esc, motor and PM07. I only soldered one esc. Then I powered PM07. After 15-20 seconds PM07 started to flame. Then I suddenly powered off PM07. Today I tried again same thing because couldn’t to find something else to do. It’s happened again.