Note 9 Invalid serial number keeps occurring.

[Dremuan]

The real serial number shows after the 1st startup after flashing but upon reboot the invalid serial appears and stays.

Invalid S/N: 279ce66c2b717ece

I know a real Note 9 S/N starts with an R and gives NFO about its manufacturing date and place of manufacture with the last 6 characters or so identifying the unit uniquely.

This is the 2nd time this exact same invalid S/N has appeared.

Anyone know what could be causing this or can recommend other avenues of investigation?

[Dremuan]

Wow, weeks and no responses on this.

Something else to add that I've found out.

If I disable 'Secure startup' under Biometrics and Security and reboot
the correct serial number reappears in Software information. But if I set it
back to Secure startup and reboot, the invalid one is back again.

Any suggestions anyone?

[SamsungAdam]

An Accepted Solution has been marked, and provided for this thread. The thread will now be locked for further replies. in hopes to keep the integrity of the thread from steering in a non-technical manner. We understand the solution marked may not be a solution for everyone, If you have a separate concern or question, feel free to Private message a moderator or post a new thread with additional details. Please note duplicate posts on similar subjects starting 2/1/21, will be removed in order to keep our community organized and make it easier for our users to find needed content. Remember that if you do make a new post, please include as many details about your symptoms as possible. Also, make sure that your title is a good summary of the overall situation that's occurring. Thank you for being part of the community!

[Stephanie Nikki · Accepted solution]

Secure Start-up encrypts the data on your device, including the settings information or any personal data. This is why you see the "token" serial number when using the secure start-up feature. Disabling it, as you've found, does revert the changes and shows you the original correct information.