Yeah, it seems like you were a bit unlucky. I mean, in case you want to give it another try at some point it would be good, if you could report back here, just out of my personal interest it would be nice to know.
Also, in case you didn’t try that already (I don’t remember exactly and don’t want to read all the 160 posts here), you could take a different bootloader, like systemd-boot or refind.
Edit: And if one day you have too much time, you can also do a Arch Linux install. At least there, as you do everything manually, you would see right away if and what is going wrong. You would still need to copy that .efi-file though.
I didn’t try other boot loaders like systemd-boot or refind, and of course if I try again where I have plenty of time I will for sure report back in here. And yes maybe I’ll try Arch Linux install also. Thank you for the support