A bunch of press on this today you can look up. Demand on the offering was much lower than expected and what materialized in prior rounds. Amazon had to sweeten the deal to get the money loaned.

Low bid to cover ratio - it's rare for bond auctions to out and out fail (that would be fairly disastrous), but you can have an auction where they successfully sell all the bonds they were trying to sell but with much less demand than they were hoping for.

That's not a good sign and it's a blatant red flag for the market