Upon upgrading the OS version, you have noticed the DefWatch scan is not running upon receiving new definitions.
The HKEY_LOCAL_MACHINE\SOFTWARE\Symantec\Symantec Endpoint Protection\CurrentVersion key is supposed to be a hardlink to the silo (GUID) reg key. However, after OS upgrade, very little is left under CurrentVersion.
SEP 14.3 RU5/refresh build
Win10 -> WIn10 22H2
Win8.1->Win-10 RS7 X64
Fresh on Win-11 22H2 with Repair,Modify Operations
Win2k16 > Win2k22
Other upgrade may be affected to.
While CreateRegistryLink actions generated by script builder were correct, the code that detects OS upgrade was using hardcoded Wow6432Node key as CurrentVersion symlink target
Upgrade to 14.3 Ru6+
If upgrade is not possible, get in contact with support to acquire a tool to fix the broken registry key. The tool is not a final solution and it should be use when needed.