Stick to version 3.2 and don't update your nvr54xx! there is a big risk of killing them and the dahua team is incompetent to fix it!
I lost two nvr dahua (bootloop) after updating my two nvr (nvr5464-4ks2 and another nvr5432-16-4ks2) I sent the nvr5464-4ks2 to the official distributor of dahua...