Compatibility of Safari with Santander Internet Banking
There appears to be a compatibility issue with Safari Version 17.0 (19616.1.27.211.1)( part of MacOs Sonoma update) and Santander Online Banking. It is unrelated to stored cookies or history.
I verified the functionality by accessing Santander Online banking with Google Chrome version 117.0.5938.149 (Official Build) (x86_64)
MacBook Pro 16″, macOS 14.0