Why are samples running on simulators - iPhone 8 slower than iPhone 12

Question

This is probably to do with project configuration settings so please would you advise me as to why a Xamarin forms project builds are running slower on iPhone 12 than iPhone 8.

I've tried:

• Compiler->Enable Optimisations;
• iOS Build->Disabling 32 bit operations as 64 bit operations;
• iOS Build->Enabling use concurrent garbage collector;
• iOS Build->Enabling Optimise PNG images;

What else could I do?

Also could it be to do with a different architectural framework needed in comparison to the samples built for iPhone 8? Your advice would be greatly appreciated.