Ok, I tried flashing TWRP the same way I think I did it the other night:You might try to flash it with TWRP. If this leads to the same issue you might at least get an error message telling you what went wrong. But to be honest the zip/script that you found seems to be the better option anyway.
I checked the fastboot oem get-hwid on my device with stock rom. It returns the following:
(bootloader) HWID = 7
(bootloader) === ID Info List ===
(bootloader) -1 : UNKNOWN
(bootloader) 0 : EVB
(bootloader) 1 : EVB2
(bootloader) 2 : SR
(bootloader) 3 : preER/ER1
(bootloader) 4 : ER2
(bootloader) 5 : prePR/PR1
(bootloader) 6 : PR2
(bootloader) 7 : MP
OKAY [ 0.001s]
Finished. Total time: 0.001s
I checked the script. What it seems to be doing here is just checking that you have the right device before flashing. If really just the get-hwid does not work and you are sure that you have the right files, you could probably just remove that check from the script and it will start flashing. (on you own risk)
But lets check first if this is a general fastboot issue.
What operating system do you use? Seems to be a linux system? What distro?
What does the command "fastboot devices" return?
If that shows a device, what does the command "fastboot oem get-hwid" return?
Also try "fastboot oem device-info".
[email protected]:~/Zenfone 8$ sudo fastboot flash boot twrp-3.6.0_11-0-I006D.img
[sudo] adgangskode for morten:
target reported max download size of 268435456 bytes
sending 'boot_b' (98304 KB)...
OKAY [ 4.072s]
OKAY [ 0.248s]
finished. total time: 4.320s
Right now I have a very expensive black mirror with the "ASUS" logo in the middle. No matter if I choose START or "Reboot to recovery" in the bootloader, it ends up displaying the ASUS logo and nothing else happens