Disable caching on a custom plugin block
I got the same issue that you, here is what it worked for me.

/**
 * Implements hook_preprocess_HOOK() for block.html.twig.
 */
function MY_MODULE_preprocess_block(&amp;$variables) {
  $blocks_to_cache = [
    'SOME_block',
  ];
  if (in_array($variables['base_plugin_id'], $blocks_to_cache)) {
    $variables['#cache']['max-age'] = 0;
  }

}


So, In my my_module.module I search if I'm displaying this block, then I clean the cache for that block. You can several block names.