Hey there!
Nice to meet you! I'm Randy, an Independent Advisor.
If Defender Offline scan restarts your PC, briefly shows the blue screen, then reboots without scanning, it likely failed to start. Since sfc /scannow and DISM found no issues, your system's fine. Try turning off Fast Startup in Power Options, or run this in admin Command Prompt: "%ProgramFiles%\Windows Defender\MpCmdRun.exe" -Scan -ScanType 2. No need to worry unless you see strange behavior.
Best regards,