Ubuntu/Lubuntu 20.04 GRUB_TIME=0 Defaults to 10 Seconds Instead of Zero

# GRUB configuration that still resulted in a count-down of 14 seconds
GRUB_DEFAULT=0
GRUB_HIDDEN_TIMEOUT_QUIET=true
GRUB_TIMEOUT=0
GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian`
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash resume=/dev/disk/by-uuid/d7623939-d093-4461-bcd9-deef3e22427c"
GRUB_CMDLINE_LINUX=""

# Option 1: Fix this bug

sudo vim /etc/grub.d/30_os-prober
### comment out the last line ###
#adjust_timeout

sudo vim /etc/default/grub
### Set these 2 lines ###
GRUB_TIMEOUT=1 # value of 1 will count as 1,0; while, value of 0 will be converted to 3,2,1,0
GRUB_TIMEOUT_STYLE=hidden
GRUB_RECORDFAIL_TIMEOUT=0

# Tested these to see no effects
# Save the $timeout and $timeout_style values set by /etc/grub.d/00_header
# before /etc/grub.d/30_os-prober misconfigures them
sudo cat << EOF > /etc/grub.d/25_pre-os-prober
set timeout_bak=\${timeout}
set timeout_style_bak=\${timeout_style}
EOF

# Reset $timeout and $timeout_style to their original values set by /etc/grub.d/00_header
# before /etc/grub.d/30_os-prober misconfigures them
sudo cat << EOF > /etc/grub.d/35_post-os-prober
set timeout=\${timeout_bak}
set timeout_style=\${timeout_style_bak}
EOF

sudo update-grub

# Option 2: install Grub customizer
# sudo apt install Grub2customizer