Great - 3600MHzTimings Table for XMP-3596 it has 1798MHz for the frequency.
Odd, that the XMP sets it to 3200MHz - perhaps BIOS update?
But - be sure you're using the correct voltage [1.45V] if you're going to try and CAS 16 16 16 38.
But you may want to try out 3200MHz @ 1.4V with the same timings and see how things go and then bump up.
**But was it a pre-build bundled/advertised with 3600MHz? If so, contact customer services if you continue to have stability issues at 3600MHz (or run memtest etc... - but again discuss this with OcUK)