Thanks. It seems that it simply takes too long to load so the profiling hits the timeout limits. We'll investigate more to see if we can improve the situation.
To expand a little: since the tested sites are not actually connected to oya.to, we don't really know what is and isn't part of the site so end up proxying and optimize every request.
Some sites redirect to different domains or paths e.g. m.example.com or example.com/en-gb. Some sites have ads and other scripts that do polling so the page never really finishes loading, etc.