I create new domain and installed wordpress 5.8.1. www.marinalopezruiz.com and any times no works fine and show Success page or Page not found, other times works but update with f5 two o three times and show me Success page or Page not found.
This sounds more like a local cache issue, try to use incognito mode. If you still have issues then, please provide more informations…
I check in chrome incognito mode and same result.
Then we need more informations, clear descriptions, basicly all you got .
Restart nginx solve the problem