Wiko Rainbow G4 invalid IMEI and 1234567890abcdf as serial

[StraffeHendrick]

Hello all,

A Wiko_Rainbow_KK_MT6582 chipset lost suddenly his EMEI number and serial.
On the frontscreen it sais "no simcard and no valid emei"
Also the serial number is changed suddenly.
See photo.
This phone had only been rooted with kingroot before , yesterday flashed it with a stock rom again, hoping it would solve my problem....

Anyone an idea how and why this happened?

Tkx