Progress bar debouncing ignores updates within a single update interval

Prerequisites

• Write a descriptive title.
• Make sure you are able to repro it on the latest released version
• Search the existing issues.
• Refer to the FAQ.
• Refer to Differences between Windows PowerShell 5.1 and PowerShell.

Steps to reproduce

& {
    [CmdletBinding()]param()

    $pr = [System.Management.Automation.ProgressRecord]::new(0, "activity", "description")

    # write the progress record once, which renders the progress bar and starts the 200 ms debounce timer
    $PSCmdlet.WriteProgress($pr)
    sleep 0.1

    # update progress record state and write it again - this write is ignored, and the progress bar still
    #  shows "description" instead of "new description", even after the 200 ms debounce timer expires
    $pr.StatusDescription = "new description"
    $PSCmdlet.WriteProgress($pr)
    sleep 1
}

Expected behavior

Progress bar briefly flashes with description and then changes to new description. Even if the update is not picked up immediately, I'd expect that the updated progress bar state should be stored and rendered on the next repaint after the debounce timer expires.

Actual behavior

Progress bar is stuck on description and new description never shows.

Environment data

Name                           Value
----                           -----
PSVersion                      7.3.0-preview.2
PSEdition                      Core
GitCommitId                    7.3.0-preview.2
OS                             Microsoft Windows 10.0.19045
Platform                       Win32NT
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0…}
PSRemotingProtocolVersion      2.3
SerializationVersion           1.1.0.1
WSManStackVersion              3.0

Visuals

No response

Start with the supplied PowerShell reproduction using ProgressRecord and $PSCmdlet.WriteProgress, then trace the progress rendering and 200 ms debounce path. Done means the second status update is retained and appears on the next repaint instead of leaving the bar stuck on the original description.