I get this all the time, even minute to minute. It is clear that Google have problems with their data feed and basically don't really care. The S&P changes from being .SPX to .INX (who calls it that). GOLD seems to be 1/100 of XAUUSD, but then it isn't. There is no DXY, and OIL's price is dodgy.
Note btw that getting =GOOGLEFINANCE(symbol,"price",date) if date is today doesn't work, you have to omit the parameter. This is often the case even after the market closes (as "price" when market is closed is effectively "close")
There are several free Chrome add-ins which provide more reliable prices. tbh, unless you are doing a large cap share-only (not ETF not funds) portfolio, I would use them. Two tips
1. Add the full GF name ie NASDAQ:AAPL rather than just AAPL
2. (Not related to symbols), use =QUERY(GOOGLEFINANCE( ....) rather than =GOOGLEFINANCE raw, to get round these little tables that =GF produces.