Serial Ports are mixed up after fresh install of 20H2 RRS feed

  • Question

  • I have a system with 4 serial ports (BIOS names \_SB.PCI0.LPCB.UAR1 to .UAR4).  When doing a clean install of Windows 10 20H2, the COM ports get mixed up in numbering (e.g. COM2) to labeling (e.g. BIOS name of \_SB.PCI0.LPCB.UAR2).  The external box labeling matches the BIOS names.

    COM1 gets (\_SB.PCI0.LPCB.UAR2), COM2 gets (\_SB.PCI0.LPCB.UAR3), COM3 gets (\_SB.PCI0.LPCB.UAR1) and COM4 is correct as (\_SB.PCI0.LPCB.UAR4).

    The COM ports are consistently messed up in the exact same orientation for every fresh install of Windows 20H2.  But this issue is not present with clean installs of 1909 or 2004. It is not present if you upgrade, say from 2004 to 20H2, via Windows Update.  Note that we can manually correct the issue in Device Manager (via Ports >> Properties >> Port Settings >> Advanced) and re-imaging from a corrected system appears to be fine for subsequent clones.  This kind of caught us as a bit strange so I though I would see if anyone else has seen the same problem or has a fix.
    Thursday, November 12, 2020 1:00 PM

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