I assume you mean you defeated the final boss and continue to play on the same campaign?
This is intended then. All special events in the game are made to be completable only once per campaign. There is no way for the game to reset all the special events and even if it could it would lead to duplicate characters or items that are meant to be unique.
You could only replay the event by using cheats to reset all campaign values for that event and then encountering her or triggering the event yourself.

Make sure your reputation with the separatists is 20 or higher then do:

enablecheats

setcampaignmetadata kumorecruited false

setcampaignmetadata kumofavor false

setcampaignmetadata kumodeath 0

setcampaignmetadata kumobetrayal false

setcampaignmetadata playerrejectkumojob false

setcampaignmetadata kumointeraction false

triggerevent kazuyakumo (Only on a separatists outpost where she is currently not present)

No no I started a whole new campaign with less mods as I deleted Enchanced Armaments (because of mask jumpscares in alien ruins). But I'll try your instructions anyway. Thanks

The commands worked as intended. It seems that the popup that captain is dead didn't show up.
Don't know what could cause this but it works now. Thanks again