Example module that adds a custom field to shipping form
Causes bad request response on shipping estimation on Mage 2.3.4
Based from offical doc: https://devdocs.magento.com/guides/v2.3/howdoi/checkout/checkout_new_field.html#add
Install:
composer config repositories.bed-m2-custom-attribute-bug vcs https://github.com/SamJUK/m2-custom-attribute-bug.git
composer require bigeyedeers/m2-custom-attribute-bug