Boot Parrot from external HDD

I’m trying to boot the Parrot Os from external HDD in UEFI mode.

So the Parrot OS was installed onto external HDD from usb device. When Graphical installer asked to remove the usb installer, Parrot OS system booted only once from external HDD. After that when I try to load from external HDD I get message “operation system not found”.

At the same time there is Windows 10 on internal HDD in the laptop. It loads perfectly every time when external boot fails.

So I can’t understand what I’m doing wrong with the Parrot that it boots only once.

When I use GParted from Live Parrot OS I see such partition:
Internal HDD with Windows 10
partition Name File System Size Flag
/dev/sda1 basic data partition ntfs 530 MiB (flags hidden, diag)
/dev/sda2 basic data partition fat32 100 MiB (flags boot, esp)
/dev/sda3 basic data partition unknown 16 MiB (flags msftres)
/dev/sda4 basic data partition ntfs 230 GiB (flags msftdata)

External HDD with Parrot OS
partition Label File System Size Flag
/dev/sdc1 fat32 512 MiB (flags boot, esp)
/dev/sdc5 boot ext4 366 MiB
/dev/sdc6 parrot-syste btrfs 120 GiB
/dev/sdc2 ntfs 100 GiB (flags msftdata)
/dev/sdc3 ntfs 100 GiB (flags msftdata)
/dev/sdc4 ntfs 100 GiB (flags msftdata)

Version of Parrot is Parrot Security 4.6
Method used to install - Debian GTK

Please post the steps followed.Also ddi you install grub in the external drive?As the external HDD is a USB device and not recognised by grub you could try booting the USB first.