Chosen Solution
I have a problem with the A51. Only the Samsung start screen is still displayed. No matter with which key combination I restart it, it only comes up to the Samsung screen. It can also not be switched off. The A51 simply starts again and it gets stuck in the start screen.
I went looking for an already existing answer for this and found it has been answered here before. I added a more comprehensive answer for those who have already tried the suggested solutions without success, if you try everything else the last resort is covered in my answer there. Good luck