Max7219 7-segment display not working

when I connect VCC pin to the 5V and GND to the GND on the Arduino MEGA, then sometimes the display glows and sometimes it doesn’t. It kinda looks like some contacts are bad because it starts to work mostly when I move it somehow, but I’m sure the problem is not in contacts as they defintely touch.

I also measured voltage on the display and it showed correctly ~5V.

Where could be the problem? Thanks

//Edit

I am using those displays to build simple autopilot panel for MSFS20 using MobiFlight. There is not any code, you just have to define what pins you connected and that’s it. But even if it turns on, then all the leds stay on.

There might be a problem since I soldered the pins into the display so I could damage the board, it’s a cheap one from China. Is there a way how to test if it’s a board problem?