In Naval Arcade Battles and Naval Realistic Battles, the “Destroy 10 units” wager does not correctly calculate progress and the multiplier. Even if you achieve ten kills in a single battle, the mission will still show as failed and consume one attempt. Furthermore, the kill count displayed in the messages—economics, battles, or ALL interface differs from the kill count in replays and the in-game scoreboard. The messages—economics, battles, or ALL interface seems to not count “critically damaged targets(重创目标已计入战果)” as kills.
Have you made a bug report yet? Or is there an existing bug report for this same issue already posted on the bug report site?
I have just submitted a report about this bug on this website.
Awesome, can you post a link to your report so we can click the “I have the same issue” button to help bring attention to it? 👍
Are you getting maps with the convoy AIs (ships that only have the ship name not a player or bot name)? shooting the convoy AI warships doesn’t count, while the AI bots that stand in for players do, which is a pain as it’s hard to tell the difference.
Yes, I think it’s a problem with the AI players. Killing AI players grants normal rewards and counts towards kill counts, but it doesn’t count towards the wager. If this isn’t a bug, they should at least mention it on the wager details page.

It is mentioned on wager PLAYERS defeated.
So in RB you need to hunt 5 Player boats down, it works just as intended.
Unfortunately, if you play top tier naval it is lacking players outside events, so best bet is low tier coastal (2.7-3.3) and you find players.