Hi @GRAY Mike ,
if you deployed a VPN Gateway using a zone redundant SKU your Public IP should be zone redundant as well.
Please check the zone details on the associated Public IP address. A Standard Public IP could be zone redundant. You can test this if you create just a Standard Public IP address.
(If the reply was helpful please don't forget to upvote and/or accept as answer, thank you) Regards Andreas Baumgarten