attacked 3 people after claiming the monthly mission it didnt update, i need to get to 1500 too so help me out pls, the cartel mission is updating, the monthly one is not

I'm also facing the same issue attacked 9 times but it isn't updating

This is a known visual issue. It will be updating, it's just that the numbers aren't high enough for you to be able to see/read them on the page yet.