VO doesn't say anything when first opening a dialog

[Nancy-Salpepi]

I noticed some changes with VO while testing phetsims/qa#1295. I am on macOS 15.6.1 and safari 18.6.

• Preferences menu
  When opening the preferences menu the first time, I don't hear anything about what tab I am on until I start to navigate with the arrow keys. Every time the menu is opened after that, VO indicates what tab I am on. I hear "Preferences menu, web dialog, X tab" before I start to navigate.

preferencesMenu.mp4

• Keyboard help dialog
  When opening the keyboard help dialog for the first time, I don't here "Close" and it is impossible to navigate the dialog without first pressing VO keys + command + H.
  Every time the menu is opened after that, I hear "Close" and can navigate with VO keys + arrows.

keyboardDialog.mp4

I also see these issues with published Greenhouse effect, so it is likely just an issue with VoiceOver.

[Nancy-Salpepi]

Just noting that there are still issues reading the keyboard help dialog with the most recent version of VO (macOS 26.0, safari 26.0).
Seen most recently in phetsims/qa#1304.