I ask for other users experience about this matter and if there is a solution, for example to uninstall the latest intel drivers and install an old one...

Your GPU is not being utilized. At all. You are running on CPU.

Start with BIOS, and work your way down from there.

Please post your solution, as others may benefit.

 for example to uninstall the latest intel drivers and install an old one...

For my part no, I have the latest and they render better than the older ones, no faulty or bluried frame anymore. Velocity is also due to the type of sourcefiles, if they are f.i. difficult to decode because they are long, more than 2K and HEVC coded.
Those type of sourcefiles render 4 times faster with my Nivida 1660 GPU compared to my Intel 630 GPU.

@arthur7 You might try making adjustments in the Nvidia control panel in case the Nvidia driver is intercepting calls to the Intel igpu. In the Manage 3D Settings section on the Global Settings tab, try setting it to default to "integrated graphics." If that works but messes up using the machine for gaming, you could instead create an exception on the Program Settings tab specifically for Vegas but you might have to add Vegas to the program list if its not there already. Also make sure Vegas is set to use the Nvidia card, however, in Preferences, Video and that Enable QSV Encoding & Decoding is checked in Preferences, General.

In the Manage 3D Settings section on the Global Settings tab, try setting it to default to "integrated graphics."

@Howard-Vigorita
I use Nvidia GTX 1660 Super, can you please tell me, which entry I should set it to "integrated graphics"?

you should go into your bios and turn off integrated graphics. You don't need intel graphics with vp17. Your nvidia card can do all the work

@walter-i. Looks like I have a section in my Nvidia control panel that's missing in yours...

The difference is use of desktop or laptop .
@Howard-Vigorita your tip does not help by editting on a desktop, for a laptop it is a possibility.

I only have one associate with an Nvidia pci plugged into a motherboard like my Asus motherboard and his Nvidia control panel looks just like it does on my Dell laptop. My guess is that if the igpu shows up in the Windows Task Manager and the Vegas video-config page, but not the Nvidia control panel, that there must be some sort of disconnect between the Nvidia and Intel drivers. Suggest a reinstall of the Intel igpu driver from your motherboard manufacturer. You might want to also check that all your motherboard bios and chipset drivers are up to date while you're at it.

Also his intel graphic is hd530. that came out 4 or 5 years ago? To use QSV you used to have to plug the motherboard video into a monitor for it to work. Working on that premise, if QSV used to work and it doesn't now maybe he needs a particular intel driver that did allow hd530 to work without monitor plugged in, or he actually did have a monitor plugged into hd530. I don't present that as primary possibility just another idea

Also his intel graphic is hd530. that came out 4 or 5 years ago? To use QSV you used to have to plug the motherboard video into a monitor for it to work. Working on that premise, if QSV used to work and it doesn't now maybe he needs a particular intel driver that did allow hd530 to work without monitor plugged in, or he actually did have a monitor plugged into hd530. I don't present that as primary possibility just another idea

Its a laptop i work on because i am always on the move, also to those you suggest the use of nvidia card, after half or an hour of editing ALWAYS it causes Vegas to crash and i believe is because of the bad buffering management...

You selected much available RAM memory for Previewing through Dynamic RAM Preview. Do have a special reason to go much higher than the default 200 MB?

On my 9900K BOTH the onboard Intel 630 iGPU & VEGA 64 GPU work together to speed-along MP4 rendering. On V16 & older versions of V17 I had to use the Intel 6373 driver (win64_25.20.100.6373) but the latest release of V17 works well with the latest Intel iGPU & AMD drivers. As others have said, I have to plug in an external monitor on the motherboard's iGPU connector so that Vegas recognizes QSV is available.

Interestingly, if I disconnect the VEGA & use QSV for renders, the iGPU-alone renders are horribly slow.... If I plug-in the VEGA, install drivers, & run QSV or VCE renders, the renders are incredibly fast. On that RedCarTest posted on these forums I get 13 seconds if I choose VCE & 14 seconds if I choose QSV. On task manager, both the iGPU & VEGA show they are utilized during renders whether I chose QSV or VCE.

Note that some motherboards & some gaming laptops may restrict using the iGPU when the Nvidia/AMD GPU is enabled. For instance, my Evoo 17 laptop enables both GPUs whereas my son's HP Omen laptop disables the iGPU. Therefore, even though my Evoo & son's Omen have the SAME I7-9750H 6-core CPUs, and similar Nvidia graphics, my Evoo renders MP4 faster...

You selected much available RAM memory for Previewing through Dynamic RAM Preview. Do have a special reason to go much higher than the default 200 MB?

Of course, when i need to preview in realtime the result of a plugin on my timeline i need about that much of memory to watch 10-15 sec of unstattering footage with effects applied on!! (Shift+B)