I have the same issue and I'd look at config.php, however, I'm not sure what needs to be done in order to enable the core plugins. Here is the plugin section from config.php. Please help, also I noticed earlier commands like the one used to clear cache in 2.16.3, doesn't work in 3.1.1 and upward, can you please tell me what is way around. thanks
// Build and store Mautic bundle metadata
$symfonyBundles = $container->getParameter('kernel.bundles');
$bundleMetadataBuilder = new \Mautic\CoreBundle\DependencyInjection\Builder\BundleMetadataBuilder($sym$
$container->setParameter('mautic.bundles', $bundleMetadataBuilder->getCoreBundleMetadata());
$container->setParameter('mautic.plugin.bundles', $bundleMetadataBuilder->getPluginMetadata());
Regards
Parvnd