Why are you surprised?
It’s been made very clear by now that tax payer security is based on need, by level of threat.
If there is a credible threat to him, security would be provided.
The same would apply for Harry, if he were in this country.
I don’t even know where Andrew resides currently?
Im assuming Windsor still, in which case wouldn’t security be encapsulated with security for the whole estate?
Rather than if he left to live in a ransom mansion and KC was still paying?
There are too many variables to make a viable comparison imo