Yes i reinstall android the phone works but i dont have root..
i use viper4android for better musik and runtastik app for running.
i believe it has something to do with magisk and viper4android.
I tried to re do everything.
Flash TWRP in slot A and then android but everytime i flasj Magisk the phone bootloops the LGV40 screen and the only way for the phone to work is to fix bootloop recovery through TWRP.
I dont understand how is it possible that the root was lost in the first place???
Afraid I've no idea. First though, when the phone bootloops, that's obvious, it's a problem. But u say you 'lost root'... how did u check that? How do u know it was 'lost'?
If you're 'starting over', with new flash kdz and flash boot+twrp to correct slot, then we know it will work to flash magisk and dm_verity, it's worked for many many people. Of course it works.
if you're trying to keep things installed, and not formatting, then it's not starting over, it's trying to make something work that hasn't worked. I don't think yer gonna narrow down what the problem is unless go all the way back to beginning.