I have the same issue. When I try to open Evernote on my iPhone, it just crashes. Every "explanation" I've seen says to sync first. Well, I can't sync because (a) there's no manual way to do so that I can find, and (b) if the app won't open, I don't know how I can sync it. I suppose I will delete the app and reinstall it and take the chance that I lose everything I've added via the app rather than desktop (which I rarely use).
It seems that there should be a "sync now" option somewhere on the web version. There are NO options for syncing anywhere. I only see mention that syncing is done automatically. But I have no evidence that this is happening. Recent clips I've saved on the phone do NOT show up in my web version.
I have the personal account and have had evernote since about 2015. I get that annual bill, believe that, but now I can't use the app.