Job queue stopped - apache issue at nginx

Hey there,
I have no idea anymore how to fix it after reading different topics, blogs, ...
The job queue of ispconfig is not proceeding anymore with the following errors:

Code:

 /usr/local/ispconfig/server/server.sh                                                                                    03.09.2023-08:47 - WARNING - There is already a lockfile set, but no process running with this pid (826214). Continuing.
PHP Warning:  Trying to access array offset on value of type null in /usr/local/ispconfig/server/plugins-available/apache2_plugin.inc.php on line 851
setquota: Setze Blockgnadenfrist auf /dev/xvda1 nicht, denn das weiche Limit ist nicht überschritten.
setquota: Setze Inodegnadenfrist auf /dev/xvda1 nicht, denn das weiche Limit ist nicht überschritten.
PHP Warning:  file_put_contents(/etc/apache2/sites-available/xx.vserver.net.vhost): Failed to open stream: No such file or directory in /usr/local/ispconfig/server/lib/classes/system.inc.php on line 865
PHP Warning:  fopen(/etc/apache2/sites-available/xx.vserver.net.vhost): Failed to open stream: No such file or directory in /usr/local/ispconfig/server/plugins-available/apache2_plugin.inc.php on line 2982
PHP Fatal error:  Uncaught TypeError: fgets(): Argument #1 ($stream) must be of type resource, bool given in /usr/local/ispconfig/server/plugins-available/apache2_plugin.inc.php:2989
Stack trace:
#0 /usr/local/ispconfig/server/plugins-available/apache2_plugin.inc.php(2989): fgets()
#1 /usr/local/ispconfig/server/plugins-available/apache2_plugin.inc.php(1897): apache2_plugin->_patchVhostWebdav()
#2 /usr/local/ispconfig/server/lib/classes/plugins.inc.php(120): apache2_plugin->update()
#3 /usr/local/ispconfig/server/mods-available/web_module.inc.php(141): plugins->raiseEvent()
#4 /usr/local/ispconfig/server/lib/classes/modules.inc.php(302): web_module->process()
#5 /usr/local/ispconfig/server/lib/classes/modules.inc.php(235): modules->raiseTableHook()
#6 /usr/local/ispconfig/server/server.php(180): modules->processDatalog()
#7 {main}
  thrown in /usr/local/ispconfig/server/plugins-available/apache2_plugin.inc.php on line 2989

I have no idea, because I use nginx and not apache.
Thanks in advance