It seems that the in-game UI mod, the display on the upper right-hand corner and the in-game death notifications all display incorrect information.
Also, the kill messages - SoAndSo was killed by SoAndSo are often wrong, but not always. I will post a replay here next time it occurs.
It's not a FAF UI mod, it's a mod you can use in FAF. Speak to the mod creator, but he hasn't updated the mod since 2017.
@FemtoZetta I've used it so long I forgot it wasn't an official mod XD
I should see if I Can fix it
I have looked into this and I am not sure where the problem lies. It must be a change in how FAF patch handles score, certainly?