Fable 5 Max hit limit, I topped up $250, then one “hey” cost me ~$20?

My Fable 5 usage on the $200 Max plan hit the limit, so I topped up $250 in credits. Then I sent a tiny test message: “hey”. On screen it showed only a few tokens used, but my credits dropped by around $20. After that, I sent actual longer messages in the same chat that used more tokens, and those cost way less. So what exactly happened here? A one-word message with barely any tokens showing should not cost ~$20. Follow-up:Now I checked my loop in CMD and it shows 847.4k tokens consumed, and somehow that co