I have been having lots of annoying issues with more recent versions of Google’s Messages including very slow loading of contacts and needing to scroll, but now every time I try to start a New Conversation, it doesn’t matter what I type, I just get "invalid contact". I’ve tried everything I’ve seen on the forums including permissions, uninstall/reinstall, clearing caches and data. I never see a conclusion, just the threads being closed. I have a Galaxy S8+. Does anyone know how to fix this?