I have used a couple of USB OTG adaptors with memory stick and even micro sd with usb adaptor and all worked fine.
Even installed Windows upgrade with it as not enough space on Tablet to upgrade directly.
Later I did a full wipe and reinstall of both systems but OTG stll works, can’t remember where but I found a driver pack that installed everything.
Try a search for X98 driver pack.
Well, thank you for your help, but sadly I have done everything and it just simply doesn’t work. I tried flashing a different bios too which made things worse because it bricked my tablet, so I had to order a reprogrammer and a clip which arrived today and I first tried to flash the 1.13 eMMC Fix bios which did not work fully work because both windows and android just simply crashed and went in a loop, then I flashed the v1.62 bios which was originally the version number that was on it which fixed the tablet and now I can boot into the both windows and android without any problems and crashes. I am happy for that but I still don’t have OTG working I reinstalled android (mirek190 v6.0 rom) still nothing, it connects to the computer no problem with micro usb cable I can browse my stuff from the android side. It charges on both android and windows without any problem so I now have no idea what it’s problem is. It looks like I will sadly have to sell it because this way I can not copy anything over to may windows side sadly with would be pretty important.