htc u11 otg usb help.....???

[CallMeKarma_24k]

I am trying to transfer a file from my HTC u11 (ocn unlocked, rooted with lineage unofficial pie, unlocked BL, s-on) to a USB stick. I have a sandisk dual usb. Well I got it somehow to read the USB there in total commander and in twrp. I tried to move the file using both twrp and total commander. It told me it was successful but when I look under the USB it isn't there and my headunit in mY car that i am trying to update the firmware file to says no file on the usb. Am I doing something wrong? Like how do I get this file to stay on usb? Do I have to format the usb? If so how?