Error with escaping in systemd file

SYSTEM INFORMATION
OS type and version Ubuntu Linux 20.04.6
Webmin version 2.021
Usermin version 1.861
Virtualmin version 7.7
Theme version 20.21
Package updates Alle installierten Pakete sind auf dem aktuellesten Stand

I have an issue, that NGINX don’t start at boot-time, even if it’s set to start in Start and Boot Section of webmin.

So I’ve looked into dmesg, and found following error:

[    2.679482] systemd[1]: /lib/systemd/system/php-fcgi-vtyreportal-xstable-com.service:5: Ignoring unknown escape sequences: "/bin/su vtyreportal -c PHP_FCGI_CHILDREN\=4\ PHPRC\=\/home\/vtyreportal\/etc\/php7\.4\ \/usr\/bin\/php\-loop\.pl\ \/bin\/php\-cgi7\.4\ \-b\ \/var\/php\-nginx\/16292023696599\.sock\/socket\ \>\>\/home\/vtyreportal\/logs\/php\.log\ 2\>\&1\ \<\/dev\/null & /bin/echo $! >/var/php-nginx/16292023696599.php.pid && /bin/chmod +r /var/php-nginx/16292023696599.php.pid"

The file that is shown in demesg have following content… (never was edited manually):

Any Idea why the issue is? … I mean I see, that the escaping is the problem - as the error-message note. But how can this happen? Is this a known Virtualmin-Bug?

I’ve moved this file to another place to see what happend.
Error-Message disappear… so it seems it was an old entry that wasn’t removed by virtualmin as expected.

But the issue, that NGINX don’t start after boot still remain.