Hello raalf,
Good day.
Is your firmware version currently on WW-V16.0610.1812.58?
If Yes. Have you tried to format it to a check?
If yes. Could you kindly tell me more details pieces of information as below?
(1.) Which OTG do you use? With SD card? Please show me the brand, model or product link.
(2.) What's your Format? ( e.g. FAT32)
(3.) Is there any error message pop on screen? If yes. Please show me your screenshot.
(4.) Do your OTG work with another Android phone?
Thank you.