Did they mail it back to you after they had sent the letter noting that they had received the application and would check it for completeness?That happened to me last year one signature and all was sent back
Sending applications back last year when things were normal would be less of a punch in the gut than it would be doing it to people now, after we have waited months and months just to hear anything back. I'm really, really hoping that they won't do this to anyone's application, short of any major components missing.