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Everywhere I've read band 28 is supported for Telstra which is 4gx and band 78 which is 5g.
Will Xiaomi Mi 11 Ultra work in Australia?
In this page we are going to show you the compatibility of Xiaomi Mi 11 Ultra with the mobile networks of Australia and with the telephony operators that provide service in Australia.
www.kimovil.com
Chinese version will cover everything a miss a band (40 5G) only which is available in global version.