Hi @valentinilas, welcome to the Vercel Community!
I see that you are using the fetch next cache as well as the Edge network caching using the headers. The revalidateTag function will purge the fetch cache but not the Edge network cache.
This means that on the initial request the data is cached both in the application and at the Edge network. Calling the revalidateTag function before the second request and 60 seconds will purge the fetch cache but not the Network cache.
I don’t think the Cache-Tag header is used by Vercel.
I hope this clarifies your doubt.