Testing with 5.5.3595 (latest download) with Visual Studio 2019 16.5.3, I’ve hit a persistent issue.
Something makes auto-complete get into a state where closing the auto-complete window de-focuses Visual Studio (like hitting alt-tab). It doesn’t do this all the time, but once it starts it’s a struggle to get rid of it (restart VS sometimes fixes it, but not always?) and almost impossible to type with. I suspect trying to do things before VGDB has finished loading a project might make it more common but haven’t been able to prove it yet and its not the only cause if it is.