How do I set a Boolean config variable to false? I can't set a boolean config value to FALSE with drush.  I'm using Drush 8.9.4.
pk@DC:~/$ lando drush config-set advagg.settings enabled 0 -y

 // Do you want to update enabled key in advagg.settings config?: yes.                                                  

pk@DC:~/$ lando drush config-get advagg.settings enabled
'advagg.settings:enabled': false

pk@DC:~/$ lando drush config-set advagg.settings enabled true -y

 // Do you want to update enabled key in advagg.settings config?: yes.                                                  

pk@DC:~/$ lando drush config-get advagg.settings enabled
'advagg.settings:enabled': true

pk@DC:~/$ lando drush config-set advagg.settings enabled false -y

 // Do you want to update enabled key in advagg.settings config?: yes.                                                  

pk@DC:~/$ lando drush config-get advagg.settings enabled
'advagg.settings:enabled': true

Why does setting it to false make it true?
When setting a boolean with drush, you need to use 0, not false.
pk@DC:~/$ lando drush config-get advagg.settings enabled
'advagg.settings:enabled': true

pk@DC:~/$ lando drush config-set advagg.settings enabled 0 -y

 // Do you want to update enabled key in advagg.settings config?: yes.                                                  

pk@DC:~/$ lando drush config-get advagg.settings enabled
'advagg.settings:enabled': false