Unable to enter bootloader (attempting to install High Sierra)

[Bastardo]

Hi,

I am unable to enter the bootloader. After a black screen, the BIOS gets shown again.

Setup:
Motherboard: Asus ROG H370-i
CPU: i5-8500
RAM: Crucial Ballistix Sport 2666, 32GB (manually set to 2666, system was proposing 2133)
GPU: iGPU (no eGPU)
OS: High Sierra
(SSD: Doesn't matter for the actual problem)

Is it likely an error with my bootable USB stick? I followed all the BIOS settings from the tutorial. While creating the USB stick things seemed to be stuck (looking onto the actual space used on the USB stick - not only the progress bar!). However I didn't touch it and after some time (hours) the dialogue for creating the bootable USB stick was gone so I assumed it might be alright. However I didn't notice any additional space consumption on the USB stick since the point when the whole process seemed to be stuck.

I have a Macbook Pro at home, can I somehow check if the USB stick is alright? I saw that a 16 GB stick is needed according to the tutorial but on mine not even 6 GB are in use. Maybe there's the error?

 

[P1LGRIM]

You should read and comply with the rules, in particular the one regarding profiles.

 

[Bastardo]

I think I now added the information to comply with the rules.

 

[Bastardo]

The USB boot stick seems normal when looking at the contents with my MBP. Actually it's under 5 GB (is that normal? Why would 16 GB be adviced if only 5 GB are needed? That seems strange)

 

[Bastardo]

No one knows the size of the contents of the USB stick?

 

[Bastardo]

I found that the machine runs Ubuntu like a charm. So either something seems to be wrong with my BIOS settings or the USB stick I used.