Google Address Auto-Complete now, once again, is enabled by default in new Shopify stores but this can be turned off very easily to enable you to use the Fetchify Postcode Lookup or Address & Validation integration.
Log In to your Shopify store
Navigate to the site Settings
Choose Checkout settings
Scroll down to the Order Processing section and deselect the option for Use address autocompletion.
We all know that if you're outside of the US Google's Address Lookup and Auto-Complete tool can be somewhat unreliable, simply due to out-of-date address data. Until late 2021 Shopify had, in fact, removed this option from its UK, Australian, New Zealand, and South African platforms because the data was so unreliable and causing more problems than it solved.
The functionality was reinstated, unannounced, around November 2021 but doesn't seem to have been automatically activated by default on all sites.