The r1 issue is known, which is what led to the creation of the versions that followed it. if r4 is the latest listed, that is the one we need to focus on.
It's been a while since confronting this issue... But there were several workarounds that resolved being able to install covered on the forum at the time of Z16 Core release.
I just tried searching the forum for these posts but... Apparently my skills in this are simply lacking...
To me, all of those point to looking in the BIOS for a fix. For example, my desktop Rampage II Extreme mobo supposedly allows booting from USB but in reality it refuses to do so leading me to resort to other measures (either DVD or installing Unetbootin on another SATA).
I have booted Zorin on the Device multiple times with the Same USB and other OS's on the same USB so I assume it's an issue with the ISO file it self I'll give a try with Ubuntu, if I have the same issue
Update: I've tried all versions of the Core except R1 -none seem to work but Ubuntu 21.10 did work correctly so I am going to flash the R1 version to see if it works, if it does we know we can remove The Razer Blade 15 late 2020 from the list