Yes you definitely have a point! have you by chance tried both ways of updating the H firmware? Maybe one or the other give you better result. I'm saying if you only have ever updated your H by downloading the firmware & then put it onto your SD card then into your gimbal maybe try updating it by connecting it to your computer with a USB cable via the GUI!! Hope you all the best of luck with this & can get it fixed without having to send it back to Yuneec!! Otherwise all I could think of is to try a different SD card, First format your SD Card, try to do the whole process using a different computer (Just in case you may have a virus & not know about it that is affecting your firmware update) & literally I think after trying all those along with everything you have already tried I think that the only other possibility is literal MAGIC!!!!! I'd still personally like to know whether others that also have similar problems as you do, have ST16's & H's that are by any chance built during the time frame or at the same assembly location, or by chance if it's possible to find anywhere whether it be documentation you have, possibly by decoding the serial # or MAC Address, or somewhere digitally on your ST16 that you can find a Build Batch # (IE just like with other products if they possibly make or assemble the H's in Batches)