@edupaulista  As far as I know, Windows does not allow itself to be booted from a drive that is connected via USB, except for "Windows To Go" installations, but those require special licensing and preparation.  If your SSD is a Thunderbolt 3 SSD, that might be different, but otherwise I'm not sure how you even got Windows to boot from your external SSD.  If I were in your situation right now just trying to get the internal SSD working again, I would disconnect the USB SSD and boot into Windows Setup.  Then at the step asking where to install Windows, I would choose to delete all existing partitions on my internal SSD until the only item listed for my internal SSD was one line that said "Unallocated space", and then choose to install to that.

@jphughan 
Today Windows 10 is already installed on my INTERNAL SSD. Operating normally.
And the EXTERNAL SSD through the TypeC port, works too.

The problem is when I start the notebook via the external SSD (it starts), but then I want to start via the INTERNAL SSD, this is where the error occurs.

But in my last test I didn't even use the EXTERNAL SSD, I just went to the BIOS and deactivated the internal M.2, tried to start, where it appeared that there was no operating system, shut down, and activated the internal M.2 again, and started windows, where the error occurred again.
(Remembering that in this test I didn't even use the TipoC port).

@edupaulista  Ok, then I'm not sure what to tell you.  Out of curiosity, what external SSD are you using?

You have not observed the situation correctly.

You cannot boot from Windows on an external SSD. You have to boot from the Internal SSD.

The way you try to boot is what is not supported and that is what is causing the problem.

I hope you install Windows on the internal SSD and boot from there only.

@jphughan 

SDD M.2 Western Digital.
It is the SSD that came in the DELL G5. But what came was a 256gb, I bought and exchanged for a 1 tb SSD WD_BLACK SN750.
I took the SSD that was in the G5, formatted it, put Windows10 inside, Adapter for TipoC.

And it was tested on another machine, an ACER, it worked perfectly.
Both WINDOWS 10 by the EXTERNAL SSD, and then by the INTERNAL SSD. (From Acer).

@RuskinF

Two things.
First, even on the DELL website, there are instructions to boot from the External SDD.
And you also have the option WINDOWS TO GO, from the EXTERNAL SSD.

Second, there is a problem without using the EXTERNAL SSD option, the error occurs when I just disable M.2, and enable it again, the error already happens. And it only works again if I format and install everything again.