This slang term coined in the 2020s has two different common uses.
It is mainly used in the context of an activity or goal that has not yet succeeded, but is fated to succeed and is currently in progress. A "success in progress".
Most often, the term is used in the romantic world when someone is fumbling major bitches but is in denial at how hard they're fumbling, saying the fumble is just a "success in progress". Usually not kissing someone you have pinned against the wall when they say you should have is a fumble, not a success in progress. But users of the phrase often use the term on these obvious fumbles, creating a sort of paradox between the actual meaning of the word and its most popular usage.
Trevor: "man you fumbled that hard."
Maximillion: "yeah dawg you fumbled hard, you had one job."
Gwendolyn: "No no, it' not a fumble! It's a success in progress I'll fix the fumble!"