Stocks app, symbol VGIT disappears

In the stocks app, most stocks and funds work fine. But when I add VGIT (Vanguard Intermediate Term Treasuries) to my watchlist, it disappears whenever I leave the app.

I read a thread about this happening with Boeing (BA) and a few other symbols a few months ago. Apple has closed that conversation, so I'm starting this new one. Apple please fix your stocks app. This should be easy.