What operating system were you using in your Nexus 5x IMEI video?
I ask because I was unable to get my Windows 7 x64 or Windows 7 x86 to install drivers for CDC Serial so IMEI fix fails.
See attached picture.(Well, may not attach but is at tiny url dot-com/sadnexus5x
I do not know where to get those CDC Serial drivers – can you provide links?
The LG Drivers in the manual instructions say they install but I do not know in which directory to find them.
(PS – also no bootloader interface driver, but I directly connected phone and used Nexus Root Toolkit to root phone manually)