I don’t know how you did it but if you are doing manual partitions you can select the /boot/efi partition that you have for current setup and eos will take over but use that current efi partition. You just have to browse to that /efi partition and mark it as as /boot during the install.
I tried all the usual fixes. None worked because eos didn’t have ‘efi’ mount on boot.
I could mount it after boot, but that isn’t the same.
Didn’t think fstab would do the trick. I had to use to additional commands to complete the operation:
What you do was install grub on mbr (MasterBootRecord) [grub-install /dev/nvme0n1p1] what is not the way to do it on gpt efi systems… where you install into filesystem (/boot/efi) same as what you have on debian systems