I found the problem. Lumberyard uses an outdated version of Visual Studio 2019, so I switched to Visual Studio 2017
I added “/Wv:18” to the CXXFLAGS under common.msvc.json in the _WAF_/settings/platforms folder. That fixed the problem for me.
Read this post I’ve made here for the answer on how to resolve this issue,
Oh you mean do the thing I already mentioned? Ok.