What happened to the updated game bar icons?

Are you talking about Game Mode in the Gaming section of Windows settings, or Game Bar? What happens when you push the Win Key+G? You can try and reset the Game Bar app. Go to the app in your Start menu, right click the Game Bar app icon, select more,
app settings, then here you can reset and repair the Game Bar app. Also check the Windows Store for any app updates for the Game Bar.

In the app there is an option to send feedback, click it and describe in detail what is wrong, then the correct team will be able to look at it and hopefully get a fix out for it.

Launch the game bar, and on the bar with the time and icons on it, there should be a cog icon, select it, and then select feedback, from there you can describe what is wrong, then send it.

Same thing here. The task bar icon flashes for a second at the same time as the top tab bar but both just disappear and refuse to open. It is only happening on my surface, though, and not my desktop. I tried to update it, but that did nothing and I couldn't
find the file to try to uninstall it.

What happens when you go to My Games and Apps, navigate to the game icon, press the menu button and then Manage game & add-ons? The update should be listed under the Update section.

Same issue here, achievement notifications are not showing, also noticed that "Notifications" is missing in the Game Bar menu (when u click the gear icon) on the latest update.