Hello,
in the following documents you can find more solutions that can fix your domain validation issue in Microsoft 365.
- Error message "Sorry, we can't find the record you created" when trying to verify a domain in Office 365 -> Solution
- Error message "Can't verify domain" when trying to verify a domain in Office 365 -> Solution
- Error message when you try to verify a domain in Office 365 -> Solution
If this is helpful, please accept the answer. Thank you.