Reverse lights not working
 

Hey all got a 03 hch cvt. Been having a repeating issue where when i put the car in reverse the reverse lights flicker. If i giggle the shifter sometimes i can get them to stay on. Sometimes they never come on. This will be the second time this has happened after repair. Had the wife take the car in for safety inspection and they replaced a solenoid on the transmission. It worked perfect for 6months then started to fail again. She cant find the reciept for 1yr warranty on it and she cant recall what it was called, google gives me no luck. Anyone got an idea what keeps failing and better yet why so frequently? Any help appreciated, due for inspection by end of the month. I am very mech and electrically inclined but without direction, breakdown, or schematics i am in the dark. No its not a fuse, short, etc. Its a slow failure of a switch 100%. Thanks ahead of time.