That's unfornutate, thanks for reporting it.
If you are able, could you run 'navigator.gpu.requestAdapter().then((a) => console.log(a))' in your browsers console? It should either give null or a GPUAdapter structure. It should at least work in chrome.
edit:
I got the same issue in Firefox myself now. I had to completely restart the browser and then it worked again. I guess you already tried something similar when cold booting a second browser?