Dell xps 13 7390 boot missing boot entry with usb type-c

Hi,

Iv'e found that my usb type-c won't identify as boot entry, only when i reboot the computer(exiting the F12 boot option setup) and immediately enter it again only then does my usb identify as a boot entry, but when i shut down the computer down and wait a half a minute(until the led light on my usb turns off) and then reboot, the entry is again missing.

Note that this behavior only happens when connecting my usb to the bottom left port, when connecting the usb to other ports i can see it and boot from it just fine.

I am using a dell xps 13 7390 running the latest bios(1.6.0) and my usb is a "SanDisk Ultra USB Type-C Flash Drive" 16gb.

This also happens on my friend's dell xps 13 9370 (also latest bios 1.13.1)

Thanks in advance!