There is no table with name 'mautic_ql.leads' in the schema. (Newbe)

Your software
My Mautic version is: 4.3.1
My PHP version is: 7.4.3
My Database type and version is: MariaDB 10.3.34

Your problem
My problem is:
I tried to send data via the Triggerdialog interface and got an error:
Letzter Ausführungs-Fehler: json_decode error: Syntax error

On my way to find the problem I executed the console-command:
mautic:plugins:update

and got a new error:
There is no table with name ‘mautic_ql.leads’ in the schema

But it exists

Logs:
Doctrine\DBAL\Schema\SchemaException::tableDoesNotExist() at /var/www/go.quatrolingo.com/vendor/doctrine/dbal/lib/Doctrine/DBAL/Schema/Schema.php:178
Doctrine\DBAL\Schema\Schema->getTable() at /var/www/go.quatrolingo.com/app/bundles/InstallBundle/EventListener/DoctrineEventSubscriber.php:27
Mautic\InstallBundle\EventListener\DoctrineEventSubscriber->postGenerateSchema() at /var/www/go.quatrolingo.com/vendor/symfony/doctrine-bridge/ContainerAwareEventManager.php:64
Symfony\Bridge\Doctrine\ContainerAwareEventManager->dispatchEvent() at /var/www/go.quatrolingo.com/vendor/doctrine/orm/lib/Doctrine/ORM/Tools/SchemaTool.php:409
Doctrine\ORM\Tools\SchemaTool->getSchemaFromMetadata() at /var/www/go.quatrolingo.com/vendor/doctrine/orm/lib/Doctrine/ORM/Tools/SchemaTool.php:116
Doctrine\ORM\Tools\SchemaTool->getCreateSchemaSql() at /var/www/go.quatrolingo.com/app/bundles/PluginBundle/Bundle/PluginBundleBase.php:47
Mautic\PluginBundle\Bundle\PluginBundleBase::installPluginSchema() at /var/www/go.quatrolingo.com/app/bundles/PluginBundle/Bundle/PluginBundleBase.php:27
Mautic\PluginBundle\Bundle\PluginBundleBase::onPluginInstall() at /var/www/go.quatrolingo.com/app/bundles/PluginBundle/Helper/ReloadHelper.php:133
Mautic\PluginBundle\Helper\ReloadHelper->installPlugins() at /var/www/go.quatrolingo.com/app/bundles/PluginBundle/Facade/ReloadFacade.php:40
Mautic\PluginBundle\Facade\ReloadFacade->reloadPlugins() at /var/www/go.quatrolingo.com/app/bundles/PluginBundle/Command/ReloadCommand.php:35
Mautic\PluginBundle\Command\ReloadCommand->execute() at /var/www/go.quatrolingo.com/vendor/symfony/console/Command/Command.php:255
Symfony\Component\Console\Command\Command->run() at /var/www/go.quatrolingo.com/vendor/symfony/console/Application.php:1027
Symfony\Component\Console\Application->doRunCommand() at /var/www/go.quatrolingo.com/vendor/symfony/framework-bundle/Console/Application.php:97
Symfony\Bundle\FrameworkBundle\Console\Application->doRunCommand() at /var/www/go.quatrolingo.com/vendor/symfony/console/Application.php:273
Symfony\Component\Console\Application->doRun() at /var/www/go.quatrolingo.com/vendor/symfony/framework-bundle/Console/Application.php:83
Symfony\Bundle\FrameworkBundle\Console\Application->doRun() at /var/www/go.quatrolingo.com/vendor/symfony/console/Application.php:149
Symfony\Component\Console\Application->run() at /var/www/go.quatrolingo.com/bin/console:42

But DoctrineEventSubscriber.php:27 shows:
$table = $schema->getTable(MAUTIC_TABLE_PREFIX.$tableName);

so I can not find the problem.

Can anyone help?

BG