Alpine: LXD unable to restart php-fpm7 from host

I’m trying to restart from host the php-fpm7 service inside an alpine container. If I restart the service within the container it restart correctly.
It works if the container is restarted, but I would prefer to be able to restart only the services as I have to do this now and then with about 500 containers, so restarting the service is way faster.

Note: restarting lighttpd or executing other commands works without issue.

Host: Ubuntu 18.04
LXD: 3.18 (snap)
Tested in Alpine Linux versions 3.10 to 3.14

I have tried:

lxc exec my-container "/etc/init.d/php-fpm7 restart"
lxc exec my-container "service php-fpm7 restart"
lxc exec my-container -- sh -c "/etc/init.d/php-fpm7 restart"
lxc exec my-container -- sh -c "service php-fpm7 restart"
lxc exec my-container -- sh -c ""

There is no .profile or .bashrc inside the container. I have verified that environment variables are the same:

lxc exec my-container -- sh -c "export"
export HOME='/root'
export LANG='C.UTF-8'
export PATH='/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin'
export PWD='/root'
export SHLVL='1'
export TERM='xterm-256color'
export USER='root'
export container='lxc'


bash-5.0# export
declare -x HOME="/root"
declare -x LANG="C.UTF-8"
declare -x OLDPWD
declare -x PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
declare -x PWD="/root"
declare -x SHLVL="1"
declare -x TERM="xterm-256color"
declare -x USER="root"
declare -x container="lxc"

No error is displayed (return code is 0) but no php process is running inside the container.
When executing from host, it is showing in logs:

NOTICE: configuration file /etc/php7/php-fpm.conf test is successful

When executing within the container, it shows:

fpm is running , pid 24732

in which ps -a shows:

22914 lighttpd  0:13 /usr/sbin/lighttpd -f /etc/lighttpd/lighttpd.conf
25109 root      0:11 {php-fpm7} php-fpm: master process (/etc/php7/php-fpm.conf)
29406 lighttpd  0:00 {php-fpm7} php-fpm: pool www

(when restarting from host, the last two lines are not shown)

The only think I can think of, is that the user in which php-fpm7 runs (lighttpd) perhaps is not being assigned correctly somewhere in the execution chain.

Is there other ways to restart it that I can test?

lxc exec my-container -T – sh -c “/etc/init.d/php-fpm7 reload”

Works perfect! Thank you!