Crash with System.Windows.Automation.ElementNotAvailableException on a view with grouping enabled, via RDP (WM_THEMECHANGED catalyst)

[SamBent]

[Port of a servicing fix for .NET 4.7-4.8]

Problem description:
Run app with custom GridView components, enable grouping.
Re-connect to the RDP session (or change the windows theme).

Actual behavior:

System.Windows.Automation.ElementNotAvailableException: Element does not exist or it is virtualized; use VirtualizedItem Pattern if it is supported. 
  at System.Windows.Automation.Peers.ItemAutomationPeer.ThrowElementNotAvailableException() 
  at System.Windows.Automation.Peers.ItemAutomationPeer.GetItemStatusCore() 
  at System.Windows.Automation.Peers.AutomationPeer.UpdateSubtree() 
  at System.Windows.Automation.Peers.AutomationPeer.UpdatePeer(Object arg) 

Expected behavior:

Minimal repro:

[SamBent]

Fix ported to 3.1.19, 5.0.10, 6.0.