When it comes to the reboots, Ivanti Patch for Windows(previously Shavlik Protect) executes a batch file that calls Microsoft patches with the /passive /norestart /quiet switches. The switches use are dependent on the patch and not all switches will be used if the patch does not honor them. Once all the patches are executed, we call the following windows API:
::InitiateSystemShutdownExW(0, const_cast<wchar_t *>(msg.c_str()), warningSeconds, TRUE, restart ? TRUE : FALSE, SHTDN_REASON_MAJOR_OTHER | SHTDN_REASON_MINOR_OTHER | SHTDN_REASON_FLAG_PLANNED)
We do not directly affect reboots. It is either done through a patch (if the patch does not honor the switches) or through the Windows API. Regrettably any problems concerning this, like the ones you are seeing would be purely environmental or an issue with a certain patch itself. Regrettably we have not heard any issues with any current patches. Our suggestion would be to discover which patch may be causing this and reach out directly to the vendor to make them aware of any issues so they may address it in a future patch. I do hope this helps.