Hi all, can anyone explain this for me?

I placed a lay bet (BF) $5 with odds of 4.98 avg and matched.

The selection failed to place so I won my bet, yet the profit was only $5.
If the selection had won the race I would be out of pocket by $20. Is that right?
I thought with odds of 4.98 I'd have $20 profit.

Cheers,
Mike