Boss Nomad.6487:

Kill counts have not updated since 10:30 GMT today.

Everything else seems to be updating.

Boss Nomad.6487:

Kills are updating again but seems like all the kills during the day were not counted at all.

Lawton Campbell.8517:

The kills are implemented via watching event logs from the map instance servers. Our event logging infrastructure had an outage earlier today (hardware failure), so the kill counts stopped being updated.

I don’t believe there’s a way to recover the lost data, unfortunately.