Linux does only boot if chosen manually on Acer Aspire

Question

I bought a Acer Aspire XC-830, which had a HDD with a pre-installed windows. In short: I installed Fedora but it only boots if I select it by hand from the boot loader.

Long story with additional details: I installed Fedora Server on the HDD and removed the windows partition during this procedure (during the setup of the Fedora partition schema). Seems that I forgot to remove the windows boot loader because it still existed after the installation (but failed to load anything). I removed it by zero'ing it with dd and reinstalled Fedora. At first I did the installation with secure boot disabled, but I managed to reinstall it with secure boot enabled (not sure, if this is important).

The problem is that Fedora is not automatically booted, after the Acer splash screen there is only a black screen and nothing happens. But if I access the boot loader via F12 it shows (only) Fedora and it is booted after I select it. So in general it works...but not on its own.

In the BIOS Boot Order Overview there is Fedora first and in the hard disk menu there is only Fedora listed. I can only boot Fedora if I select it manually in the boot loader, which also does only list Fedora.

Output of lsblk after booting Fedora:

NAME                                          MAJ:MIN RM   SIZE RO TYPE  MOUNTPOINT
sda                                             8:0    0 931.5G  0 disk
├─sda1                                          8:1    0   600M  0 part  /boot/efi
├─sda2                                          8:2    0     1G  0 part  /boot
└─sda3                                          8:3    0 929.9G  0 part
  └─luks-5f9db553-2fea-4424-a9e4-c5e2c153a6f0 253:0    0 929.9G  0 crypt /home
sdc                                             8:32   1   3.9G  0 disk  /mnt
sr0                                            11:0    1  1024M  0 rom
zram0                                         252:0    0   7.6G  0 disk  [SWAP]

Output of efibootmgr -v:

BootCurrent: 0000
Timeout: 1 seconds
BootOrder: 0000
Boot0000* Fedora    HD(1,GPT,ae59bf86-1a9c-4dc1-95cf-bbea6f9b2b3a,0x800,0x12c000)/File(\EFI\fedora\shimx64.efi)

Looks all fine to me but still Fedora is not booted but the system halts on a black screen. I read some posts where people had similar problems to install Linux on an Acer device (some mentioned some kind of hard coded BIOS towards windows?), but they all wanted to achieve a dual boot system and still got windows installed (or this). And most problems were launching installation of Linux from USB due to secure boot.

To make things stranger there are two additional curiosities I noticed:

1. If I hit F12 during startup to get to the boot loader but then hit escape ("to boot using default") it continues to boot Fedora...so somehow default works but not from start on?
2. If I set the BIOS' supervisor password and set the security option to "System" (Check password always), it boots Fedora after I enter the supervisor password at start (without hitting F12 to get to the boot loader)

Answer 1

Is there a fast boot option in this BIOS? Try disabling it if so. Is the BIOS updated to the latest? Try updating if not. Is there a setting in the BIOS to enable UEFI only or Legacy only? Try toggling this to see if it helps. There may also be a setting that tries UEFI and falls back to Legacy, try this as well. You may also try different distros and see if they behave the same. Ensure you are using the latest version of Fedora as well as the 64bit version(if that is what your hardware supports)