STunnel fails to generate an rc script
In some circumstances the STunnel package fails to generate a default certificate as part on it's install script and that in turn means it never creates /usr/local/etc/rc.d/stunnel.sh.
That means it cannot be started/stopped from the webgui and does not start at boot.
So far I have only been able to replicate this on arm64 (SG-1100).
The error generated by the install script is:
Jul 30 13:04:11 php /etc/rc.packages: Error creating stunnel certificate: openssl library returns: error:0E06D06C:configuration file routines:NCONF_get_string:no value