Installed aftermarket Android Head Unit in my wife’s CX-5 = backup camera worked perfectly for 2 weeks and then all of a sudden the backup camera was not coming up on the display. I tried putting the car back in park then back in reverse. Turning the car off and back on. Disabled the battery for an hour to try for a reset, but it was still not working. Removed the unit and made sure all connections were correct - still nothing. Googled and most people said the issue resolved itself… been 5 days and it’s still not changing screens when put in reverse
Time to replace the head unit.
Yeah, if the connections are good you probably got a defective unit. It happens. If possible, take it back for a replacement.