Checkout block location
Most block types such as checkout bump and dynamic custom fields have the option to specify a block location. If you do not select a location, all blocks will default to dynamic. Block locations allow for showing different blocks of the same type in different sections of checkout. For example: say you want to show a required checkbox (custom field) in the main content area but an optional gift note (custom field) in the sidebar, one can be set to block location 1 and the other to block location 2.
Make sure your block location within Checkout Blocks is the same as within the checkout editor or the block may not show.
1. First, select a location number under Visibility > Checkout location, for example 3:
2. Second, select the same location for the block within the Checkout Editor making sure they match, for example 3: