Unable to boot after installation - multiboot with grub

after successful installation, i created grub menu entry pointing to EFI/org.clearlinux/bootloaderx64.efi on boot partition. Everything was fine, but after reboot and select ‘clear linux os’ i saw only ‘Booting in insecure mode’ . Some year ago uefi was set to insecure mode. It i changed to secure mode, but with no results, my computer still runs in insecure mode. But insecure mode is certainly the reason?
I used this tutorial https://docs.01.org/clearlinux/latest/tutorials/multi-boot/dual-boot-linux.html#boot-clr-method-2. I dont want to replace boot.

/dev/sda1: UUID=“8C01-6014” TYPE=“vfat” PARTLABEL=“CLR_BOOT” PARTUUID=“c5e007c8-4157-4f4e-93c2-189444adcc88”
/dev/sda3: UUID=“fb6ffbe2-ccf7-485d-9023-75a0304ecef0” TYPE=“swap” PARTLABEL=“CLR_SWAP” PARTUUID=“f4dbaaf4-9643-4fa9-b686-d28bb30693d1”
/dev/sda8: UUID=“d670b8ce-41d3-4874-a6b3-691a3550314e” TYPE=“ext4” PARTLABEL=“CLR_ROOT” PARTUUID=“7041bbad-acc5-4b55-ad65-b83f2941e55a”

no ‘clear linux’ on In uefi boot manager, reduced directory tree:
├── EFI
│ ├── BOOT
│ │ ├── bkpbootx64.efi
│ │ ├── bootx64.efi
│ │ └── fbx64.efi
│ ├── org.clearlinux
│ │ ├── bootloaderx64.efi
│ │ ├── freestanding-00-intel-ucode.cpio
│ │ ├── freestanding-i915-firmware.cpio.xz
│ │ ├── kernel-org.clearlinux.native.5.4.6-883
│ │ └── loaderx64.efi
│ └── ubuntu
│ ├── BOOTX64.CSV
│ ├── fw
│ ├── fwupx64.efi
│ ├── grub.cfg
│ ├── grubx64.efi
│ ├── mmx64.efi
│ └── shimx64.efi
├── loader
│ ├── entries
│ │ └── Clear-linux-native-5.4.6-883.conf
│ └── loader.conf
└── Temp

It strange, but when i chose uefi without secure mode once again, after that i am able to see uefi boot managet. But i have another trouble: when i select clear linux on menu, nothing boot. Instead of this computer just reboots.

I know the reason. I have been using kernel 5.4.6-883. But i swtiched to older lts and now its work,

I’m not sure why the 5.x kernel would be an issue but I can tell you that Clear Linux does not fully support secure booting yet. It is being worked on though. You can read the discussion at https://github.com/clearlinux/distribution/issues/234