After upgrading to the Insider Preview, an issue has arisen with the Performance tab in Task Manager

This sounds like an issue with the latest Insider Preview build rather than your GPU driver, especially if Device Manager shows the graphics card is working normally. A few things you can try are restarting the graphics driver (Win + Ctrl + Shift + B), updating or reinstalling the GPU driver, and checking if the issue persists after a reboot. If it started immediately after the Insider update, it's also worth submitting feedback through the Feedback Hub, as Insider builds can introduce temporary bugs like this. Hopefully, Microsoft addresses it in a future build.