This is completely normal and nothing to worry about.
The reason for this is the exchange’s limitations for price step and volume step.
To realize your trade despite these limitations, you will sometimes see a minus in your deal.
The following link from the official 3commas FAQ tries to explain it in more detail: https://help.3commas.io/en/articles/3109061-why-there-is-a-minus-in-profit-in-some-deals