I can confirm that issue. I'm trying to use Visual Studio 2019 (Windows AND Mac-Version). On both versions it crashes immediately when Debugger is connected on Xamarin.Forms Android application. But it works with VS 2017 (at least on Windows).
Still hoping for a quick fix. Thanks!
I am also facing the same issue in Visual Studio for Mac 2019. I am getting something like this while debugging.
[libc] Fatal signal 11 (SIGSEGV), code 1, fault addr 0xbc in tid 9261