unbound binding problem after restart

[FritzS - gmx]

Sometimes unbound could not bind his port 53 after restart.
After this unbound are not listed as process in the CPU process dump too.
A second start command tells process are running.
So I must restart my mac that it works.

I obsurved unbound start short under user root and changed quickly to user unbound - I think to be able to bind his port.
Are the way to use user and group ID's under 500 a better way?

If 'yes' could UID's from existing users and groups are changed (1)?

(1) In
https://spatof.org/blog/2013/8/unbound-on-osx/
tells the author:
»Unbound will run as a system daemon so we need to create a new user and group. First we need to find a free unique id for our user and group in the range 1-500 (this range is reserved for system accounts); pick a random number between 1 and 500 and check if it's taken, for example `451`: :« 

Is this true for my current macOSX -  OS X El Capitan, version 10.11.6


The UID's
user: unbound 507
group: unbound 502

This commands I use to restart unbound:
$ sudo /opt/local/bin/port unload unbound
$ sudo /opt/local/bin/port load unbound
or
$ sudo /opt/local/etc/LaunchDaemons/org.macports.unbound/unbound.wrapper stop
$ sudo /opt/local/etc/LaunchDaemons/org.macports.unbound/unbound.wrapper start
or
$ sudo /opt/local/etc/LaunchDaemons/org.macports.unbound/unbound.wrapper restart

My Mac: OS X El Capitan, version 10.11.6
I use Little Snitch too
https://www.obdev.at/products/littlesnitch/
My mac firewall are on, but unbound are allowed. 

PS: An another unbound problem are resolved
https://trac.macports.org/ticket/52918