Hi Fred_Rt,
Thank you for reaching Microsoft Community.
Please boot the device first to the UEFI screen. You may check this page for the steps on How to get to the UEFI settings. Once you are on the UEFI screen, choose Devices. Under Devices, please check if Front, Rear and IR Camera is enabled. If it is already enabled, disable it then go to Exit > Restart now. After the Restart, boot the device again to the UEFI screen and enable the camera options then check if the issue persist.
If still the issue persists, please run these steps below:
1: Run Surface Diagnostic Toolkit and check Windows Update
2: Update drivers and firmware
Check what is the current OS Build of your Windows version by going to Settings > System > About.
Go to Download driver and firmware for Surface, choose Surface Pro 6 then click Download on the next page.
Choose the .msi file that matches your current OS Build and click Next.
After downloading, run and install the .msi then Restart.
3: Run System File Checker Tool in Windows 10
If in case the issue still persist, I suggest that you re-install Windows on the device using a USB recovery Image. This option will reimage the entire device and reload Windows including the drivers and firmware. It is the most complete form of Reset and it will wipe out everything on the device so you might need to back up your files first. You will need also a 16GB/32GB of flash drive that must be formatted into FAT32 prior to downloading the Recovery Image. If you like to try, you can follow the steps provided below:
How to Download, Create and Use a USB recovery drive
To download the Recovery Image:
Visit the page to Download the recovery image for your Surface
Sign in with your Microsoft Account
From the list of Surface devices available, select the device that you need a recovery image for
Please note that while you will only be presented with devices that are currently registered on your account, you will also be presented with the option to get an image for a different type of device. If you try to use this option, you will be prompted to enter the serial number for that device
Download the recovery image using the button on the page
When the download bar pops up at the bottom of your screen, save the file in a location you will be able to find it.
Format USB Drive:
Insert your USB drive into the USB port of your PC.
From the desktop, open File Explorer
Tap and hold or right-click on the USB drive and choose Format
Select FAT32 as the file system and enter a Volume label to name the USB drive, such as RECOVERY, and then tap or click Start
Tap or click OK to erase the contents of the USB drive
Tap or click OK when the format is complete
Create a recovery drive:
On your Surface or PC, open recovery image that you downloaded by double-clicking it or right click then select Extract and then Extract all.
Select the USB drive you formatted earlier for the location and click Extract.
Use a USB recovery drive to reset your Surface:
Shutdown the Surface
Insert the USB recovery drive into the USB port
Press and hold the volume-down (-) rocker
Press and release the power button
When the Surface logo appears, release the volume-down (-) rocker
Surface will start the recovery software on the USB recovery drive
When prompted, choose your language options and keyboard layout
Select Troubleshoot
Select Recover from a Drive. Choose Remove Everything and Fully Clean the Drive. Recovering this PC.
If prompted, select Repartition the drives
If prompted for BitLocker Key, tap Skip this Drive
Hope this helps.