After upgrading to Android Studio 4.0.2, I was no longer able to use the Android Studio Profiler with my Xamarin.Android app, as instructed here (Microsoft Docs).
It will tell you that the "Default Activity" could not be found; a google search suggested that I adjust my build configuration to use a default activity, but doing this just changes the error to "Unable to determine application id".
Reverting to Android Studio 3.6.1 fixes the issue and everything works as expected by following the instructions in the Microsoft Docs I linked above.
Additional context: minimum android version API 21, target version API 28, shared runtime is disabled, building to OnePlus 7T
Unsure where to raise an issue for this, but please let me know if I can provide any more information about the issue.