Every candidate is supposed to read the preparation guide:
At the end of page 1 it says:
"Read the FAQ or chat with our support team if you have questions during exam preparation"
Then there's a button to "Contact Support" which initiates a live chat...
That's what you should do...
I also had the same problem today, and I have solved it by redownloading ISO file.
If you use liveUSB which has been created a long time ago , maybe ISO file is old.
At first, I booted liveUSB created about 1 year ago.
Today(2022-02-28), I downloaded rhrexboot.iso and created newer liveUSB.
When I boot and close the settting window, I managed to go on to the remote exam screen.
I hope you will solve the issue.
Anyone ever seen/resolved the error "The onboarding process could not be initialized"? I've used the same laptop/usb ISO image for my past 2-3 remote exams without issue but for the past 3-4 days it has not worked. It boots up fine goes through the settings (network/sound/screen etc) and then errors out with a popup RHRE-20210309., I download an older ISO image to test with to no avail and tried to download the newest ISO again and recreated the usb disk. I was supposed to have my next exam on 4/4 but i had to cancel due to this one. I also verified the static network IP/link is fine