Magento2 : user define customer attribute not save value while create / save from admin
looks like the issue was due to the fact your attributes are not assigned to the customer attribute set.
the following code is needed in your install: I added full code for you at https://bitbucket.org/magstaging/newcustomerattribute
$eavSetup->addAttributeToSet(
CustomerMetadataInterface::ENTITY_TYPE_CUSTOMER,
CustomerMetadataInterface::ATTRIBUTE_SET_ID_CUSTOMER,
null,
$attributeCode);