Is your 1700 overclocked, or at stock clocks? The 1700 should be overclockable up near 4GHz, which might make a difference. Some of those scores might have been for heavily overclocked GTX 1080s as well. And we are talking about running the same resolution and settings, right?
There could be other things like thermal-throttling at play here too. You might need to check temperatures and cpu/gpu utilization during the benchmark to see whether there might be some other factor at play. And of course, close any other applications like web browsers while running it, since things running in the background could impact performance as well.