Just following up here to share that the bug report has since been closed. The developers of the Keap app integration on Zapier have confirmed that for the address fields that were left blank when updating other address information, it is the expected behavior for it to clear the existing value for those blank address fields.
In case you missed the email notification about this, here’s what you need to know:
“When updating an existing contact, blank fields in the billing, shipping, or “other” address sections can erase existing information. For example, if any billing address fields contain values when the action runs, but “Billing Address City” is left blank, the existing “Billing Address City” value on the contact will be erased instead of remaining unchanged.
This means that when updating any billing, shipping, or "other" address fields, you need to have values for all fields.
Our partners at Keap have confirmed this is how the action is intended to work.”
Hope that helps. If you run into any further issues feel free to start a new topic in the Community here or reach out to our Support team directly and we’ll be happy to assist. In the meantime, happy Zapping! ⚡