How can I unset classes?

Hello,

I installed the module and added some classes in some blocks. The problem is that I need to load this blocks in various node types (programatically) and unset the classes that I configured for this blocks.

In my theme.theme file I used this code:

//Get people block
$block_pople = Block::load('personas');
$block_pople->unsetThirdPartySetting('block_class', 'classes');

$block_people_content = \Drupal::entityTypeManager() ->getViewBuilder('block') ->view($block_pople);

$variables['people_block'] = $block_people_content;

If I debug the result of the $block_pople, I see that the classes are removed well, but when I render the block in the node, the classes are present. I'm doing something wrong?