Error Log Entries "Error while sending QUERY packet" after upgrade from 17->18

Hello guys,

since updating from Nextcloud 17 to 18.0.4 I keep having Error Log entries that didn’t appear before:

Error while sending QUERY packet. PID=4318 at /www/htdocs/XXXXXXX/XXX.XXX.de/3rdparty/doctrine/dbal/lib/Doctrine/DBAL/Driver/PDOConnection.php#88

I have searched the net and found out that it seems to be related to having more queries to the database than the server can handle.
This never happened before the upgrade and my nextcloud instance isn’t heavily used. It is more of a family cloud.
It runs on shared hosting with all-inkl.com so my options on the server side are somewhat limited.

Do you have any idea what I could do to solve the issue?

Nextcloud version 18.0.4
PHP version 7.3

config.php:

<?php
$CONFIG = array (
  'instanceid' => 'xxxxxxxx',
  'passwordsalt' => 'xxxxxxxxxxxxxxxxxx',
  'secret' => 'xxxxxxxxxxxxxxxxxxxxx',
  'trusted_domains' => 
  array (
    0 => 'xxxxxxxxxxxxxxxxxxxx',
  ),
  'datadirectory' => '/www/htdocs/xxxxxxxxxx/xxxxxxxxxxxxx/data',
  'overwrite.cli.url' => 'http://xxxxxxxxxxxxxx.de',
  'dbtype' => 'mysql',
  'version' => '18.0.4.2',
  'dbname' => 'xxxxxx',
  'dbhost' => 'localhost',
  'dbport' => '',
  'dbtableprefix' => 'k1wRj_',
  'mysql.utf8mb4' => true,
  'dbuser' => 'xxxxxxxx',
  'dbpassword' => 'xxxxxxxxxxxxx',
  'installed' => true,
  'logtimezone' => 'Europe/Berlin',
  'tempdirectory' => '/www/htdocs/xxxxx/xxxxxxxxxxxx.de/tmp/',
  'maintenance' => false,
  'theme' => '',
  'loglevel' => 2,
  'mail_smtpmode' => 'smtp',
  'mail_smtpauthtype' => 'LOGIN',
  'mail_from_address' => 'nextcloud',
  'mail_domain' => 'xxxxxxx.de',
  'mail_smtpauth' => 1,
  'mail_smtphost' => 'xxxxxxxx.xxxxx.com',
  'mail_smtpname' => 'xxxxxx',
  'mail_smtppassword' => 'xxxxxx',
  'filelocking.enabled' => true,
  'updater.release.channel' => 'stable',
  'updater.secret' => 'xxxxxxxxxxxx',
);```

I remember that other users have reported similar problems in the past to to a restriction of the number of sql queries within a time window and a limited amount of memory. As far as I remember the recommendation was, to upgrade your hosting package to a one which doesn’t have that restriction or to switch to a different hoster. Afaik ot isn’t possible to restrict the number of sql queries within Nextcloud.

Thanks for your answer.
However, this never happend with the version before and the cloud has seen busier times. So it is either a bug of the new version or at least something was changed that creates this behaviour.
Any other ideas what could be done?