Unable to boot from usb: why is internet recovery triggered if I want to boot from a pendrive just because internet recovery does not work?

Hi there,

After several attempts to fix a "minor" problem with Big Sur, I deleted volumes "Macintosh HD" and "Macintosh HD - Data" from my drive (keeping a bootcamp volume still there) in order to enter recovery mode and perform a clean install for Big Sur. By the way, this was the solution given by an apple support technician.

The problem is that, no matter what I do, internet recovery does not work after the volumes deletion. I can see the spinning world and, as soon as the progress bar is completed, I get a -1008F error that is supposed to be a connection error.

I do not think it is a connection error, at least from my side, because I've tried to connect via Ethernet and 2 different Wifis, all of them working as intended with many other computers and devices. Furthermore, my surviving bootcamp volume with Win10 installed is still bootable and can perfectly make internet connections on the same hardware and networks. So I do not either think it is a hardware problem, as has been concluded by another apple support techi.

In the meantime, I was also told by apple support to phisically deliver my MBP2018 in order to let them review and repair the hardware problem. Funny thing is that my guaranty period concluded just 2 weeks ago (it can't be true!!!!), so I have to pay 59€ just to let them see what happened. Nice. I'm sure its not a hardware problem! It was working perfectly on Catalina and it is still working perfectly on Windows 10 with bootcamp! By the way, the diagnosis tool executed booting with a pressed D says that there are NO problems at all.

In the meantime, I tried to make a bootable USB from another Mac and it seems to be properly created but, when I try to boot my MBP from such usb device, instead of loading the installing program from the USB (this is what I expect!) the spinning world from internet recovery start again (why??????) leading in the already said -1008F error. Why on earth should I create a bootable USB just to start again a recovery from internet? NON SENSE.

All in all, I think that the problem is related to the process I followed to erase the volumes, deleting just two of them instead of the whole disc (I wanted to keep the bootcamp volume alive) but, anyway, the question is that my Mac is unable to be recovered and I am really frustrated, bored and angry :(.

I started with a problem with Safari and App Store and now I have a Mac working only on Windows and some less money in my pockets because I followed the steps that apple support techs recommended me to do :(.

I really appreciate in advance any comments or help you can figure out.

Best regards