Is SecureBoot enabled?
With my wife's new HP Core-i5 8250U I used the F27 live install method from
a USB stick and everything "just worked". I inherited her old Acer i5-6200U
and it was quite a bit more work.
I had to disable SecureBoot in order for it to boot from the USB stick (but
left it in UEFI because if you don't the installer will not setup /boot for
UFEI). Everything installed fine including resizing my Win10 main partition
to make room.
Afterwards I spent about an hour trying to get it to boot the right way
instead of skipping over Fedora and booting Windows 10. With this
particular laptop you have to go into the BIOS and tell it which EFI file
is trusted, and I chose grubx64.efi as you did and then you can give it a
Then I had to change the boot order to put it in front of the "Microsoft
Boot Loader". After that it works just fine.