Unable to save content language configuration My Drupal 8 website is multilingual and has many entity type bundles for nodes, taxonomy terms, paragraphs, media et cetera. This leads to a content language settings form (admin/config/regional/content-language) with more than thousand translatable-checkboxes.

Currently I'm not able to save this form. In the first place the form seemed to be successful submitted but changes have not been saved. This was caused by insufficient php setting value for max_input_vars, which could be solved by setting it to 6000. Now I'm struggling with a timeout. After submitting the form the request fails after some minutes.

Here are the php settings of my Drupal VM:

php_version: "5.6"
php_memory_limit: "1024M"
php_realpath_cache_size: "1024K"
php_opcache_enabled_in_ini: true
php_opcache_memory_consumption: "192"
php_opcache_max_accelerated_files: 4096
php_max_input_vars: "6000"
php_max_execution_time: "720"
php_post_max_size: '64M'


How can I get around this issue? Which resource bottleneck could cause this?
I tried the max_input_vars fix and that didnt work (i have alot of custom entities on the page and was hoping this would work).
I had to check the entity, pretend it was called MyCustomEntity in 'Custom language settings' at the top... but also scroll down to the individual MyCustomEntity settings further down on the page, and also check that checkbox. When I saved, now it worked