There's no doubt that the word is primarily translated as "grace" (130 times in the King James version). However, there are a few times (6 in total) that this word is translated as "favor".
Luke 1:30, Acts 2:47, Acts 7:10, Acts 7:46, and Acts 25:3 are the other five places (beyond the passage in question).
If you look at all six passages, the idea used is having found "grace" with someone, "grace" for someone, or "grace" towards someone.
The idea is always grace in motion.
If we look at the English definition of "favor" it might help make this translation clearer:
Merriam Webster: favor
- (1): a friendly regard shown toward another especially by a superior (2): an approving consideration or attention
- archaic appearance
- a : gracious kindness; also : an act of such kindness
The first definition shows that "favor" is a regard shown
toward another. This is the same type of concept shown in the six passages above. Furthermore, the third definition shows that the idea of favor is connected with grace: "gracious kindness".
This link between "favor" and "grace" can also be seen in that second definition of "grace" is "approval, favor".
Ultimately, "finding grace with God and man" and "finding favor with God and man" are the same. If someone offers you grace, then they favor you. If someone finds favor with you, they will offer you grace. These two concepts are inextricably linked, to the point of being able to translate between the two.