I could not update the Kernel. Resolved. For newbies!
If there is someone who, like me, has trouble updating the core of his mageia (in my case Mageia7), just do this:
as ROOT
a) # urpmi --clean
b) # urpmi - auto-update
That simply resolved me in 3 or 4 minutes 12 days of uncertainty and concerns because the system could not update the kernel-desktop-5.4.12-1 .mga7-1-1.mga.mga7.x86_64 correctly
I hope it serves for at least one person with a similar case.