Completed installation of Ubuntu on Lenovo 100S. Will not boot

The Ubuntu installation completed without any errors. At the end it said to remove the installation USB and restart, which I did, but it won't restart.

I'm installing on a Lenovo 100S-14IBR

Steps that I used:

• Downloaded Ubuntu 22.04.2 LTS
• Used Rufus to create a bootable USB
• In UEFI settings, I set the boot order and disabled Secure Boot
• It booted from the USB
• I selected to install (not "try out")
• I chose the destination drive. I chose the 64GB eMMC drive, not the 256GB SSD.
• I chose to delete all existing partitions (not keep existing windows install)
• For the next 1/2 hour, it installed all the software
• It asked me to remove the installation USB and restart the computer, which I did.

Ubuntu will not start up. I thought maybe I installed on the wrong drive and that I should have used the 256GB SSD.

I tried re-installing using this drive. But I immediately got errors: "error during write on /dev/sda" and "Failed to create a file system, the EFI file system creation in partition #1 of scsi1 (0,0,0) (sda)"

I then left the computer for a while and when I came back, Ubuntu was up and running! I have no idea how. I worked for a while with Ubuntu and installed VsCode. All seemed well. Therefore, I deleted this question.

But later that day, I powered the computer off. Now it will not boot into Ubuntu, no matter what I try. I tried changing the boot order. This is my current boot priority order:

Ubuntu
USB HDD: PNY USB 2.0 FD
Windows Boot Manager
USB FDD
ATA HDD
ATA HDD
ATAPI CD
eMMC Card0: SanDisk iNAND 64GB
SD Card1
SD Card2
USB CD
PCI LAN
ATA HDD: DISK

When I take the boot USB out and press the power button, The screen briefly gets bright, then displays "Reset System" in tiny print in upper left of screen and then screen goes black. It keeps going through this cycle.

If I leave the boot USB in the drive, it only boots into the Grub menu.

Try or Install Ubuntu
Ubuntu (safe graphics)
...

======= PROGRESS =========

I was able to get Ubuntu to boot again. But not normally by just pressing the Power On button. Now I need to first press the "NOVO button" to get this menu:

Normal Startup
BIOS Setup
Boot Menu
System Recovery

Up until now I was always selecting "BIOS Setup" and changing the boot order there. This time, I selected "Boot Menu" which shows this:

1. Ubuntu
2. WIndows Boot Manager
3. eMMC Card0 Sandisk iNAND 64GB
4. ATA HDD: Intel SSDSCKKF256H6 SATA 256GB

Setting the eMMC card in the BIOS setup was not working, so now I selected number 4, the 256GB drive. Now Ubuntu booted up!

I'm glad that I didn't brick the PC. But I still don't know how to boot up Ubuntu without going through this process each time. The 256GB drive doesn't appear (as such) in the BIOS boot priority menu. Maybe one of the other entries refers to it.

But also, it appears that I may have messed up the setup of these disks, since Ubuntu itself should still be on the 64GB drive. Why do I need to boot from the 256GB drive in order to get to it. And how would I fix this?

======= SOLUTION ??? ======

I moved the first "ATA HDD" entry in the BIOS boot priority list up to the top. Now when I just hit the power on key to power up, it boots into Ubuntu. The solves my main issue of being able to easily boot Ubuntu. But I should still try and find out why I need to boot off the 256GB drive when Ubuntu is on the 64GB drive and fix this. I could have problems later because of this.

I ran gparted from the internal Ubuntu. Here are the results:

I am still confused. It's showing that the 64GB drive contains a boot partition and an ext4 partition that should contain Ubuntu. The 256GB drive has an ntfs partition for data. So why do I need to boot from "ATA HDD: Intel SSDSCKKF256H6 SATA 256GB" which would be the data drive.

I'd like to reformat the 256GB drive as ext4, but I don't know if doing that will again prevent Ubuntu from booting.