I have a xDuoo Nano D3 with Firmware V1.6 installed. There is an issue with any track which has a duration greater than 60 minutes. When the currently played value goes over 60 minutes then the value returns to zero. This means that when you resume play after switching off it commences only in the first 60 minutes. For example if you are at 65 minutes into listening a 90 minutes track, the display shows 00:05 / 01:30:00. If I switch off at this point and turn the player back on, the player will resume at five minutes 00:05 not 65 minutes.