Work Item Customizations

Be sure to read the documentation about how Bugs behave differently in ADO depending on how they're configured for the project (i.e. peers or children of Items). I'm using custom Fields and custom workflow states without problem for years, but you really need to be across the documentation, and trying your changes out in a test-project first ;):
https://docs.microsoft.com/en-us/azure/devops/boards/backlogs/manage-bugs?view=azure-devops