Yes, I have the same s@!t situation, after I received the cable I realised that I have to solder. It is a cheap component I don’t want to spend time on those tiny parts. Just looking for another supplier. Never met with this issue with flex cable.
Alright, the consequence is: The aftermarket battery has so poor performance, all the screens was okay. The bottom of the screen is warm caused by backlight flash. solution in my case is: another new battery from different vendor
In my case, after a screen replacement, i pushed the Digitizer connector with a tiny bit force more, than the connector accidentally damaged. Was easy to fix, with a metal tweezer, hope it helps ;)
I asked my friend after I detected this same issue with an iPhone SE. He is an *original* LCD refurbisher from Hungary, and he said, yes this happens when you disconnect the screen from the phone. It will appear because the screen need to be “charged up”! So don’t worry about the flickering backlight
Guys, probably the NON-official LCD is the problem, not the quality of the cables. 100% the cheap screens are the cause of this issue. And also you can see different color depths( brighter etc.)