Did you input all your investments into the Vanguard wizard? If not, then Vanguard is only using the money they know about. If so, then sounds like the time frame you put in is too aggressive. Vanguard also tells me I need more $$, but I’m not telling it all the $$ I have so I expect this.
What's the issue?
We need to 2x the 401k deferred contribution limit. But the govt would rather tax that away and shovel it into the crashing dumpster fire that is SS