Disable USB power saving for booting from USB

Having issues booting from USB connected SSD and disabling this in the Linux Kernal seems to solve the issues of the disk becoming unavailable.
Edit /etc/default/grub and change the following line:
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash usbcore.autosuspend=-1"

Update the config with: sudo update-grub

Reboot

Thanks to this post.