Where to download older versions of Xamarin.iOS? In this specific case Xamarin.iOS 14.8.0.3

For xamarin.ios-14.8.0.3.pkg:

https://aka.ms/xvs/pkg/macios/14.8.0.3

This is what you might be looking for.

https://github.com/xamarin/xamarin-macios/releases/tag/xamarin-ios-14.8.0.3

For anyone still looking, I have found a list of all Xamarin downloads in case you need to test on an older build:

https://www.cnblogs.com/jasondun/p/12629634.html