Same problem for me. I can't buy any games I have tried on device, on my phone and on the web all with the same error. I even removed payment method and added a new one and I also changed my pin but still no good.
Here's the error I get in addition to the "temporary problem" statement: "GraphQL server responded with error 207801." Just purchased -- can't buy games & the triggers don't function. I guess the Quest is to find one that works!
I had a very urgent NEED to purchase Beat Saber from the Quest 2 store. It did not work on the 27th, so I waited. The next day my purchase worked. Excuse me while I get back to Beat Saber.