Death statistic gone and unable to manually change back (new value gets inserted somehow)

Hello,😁

A while ago I noticed the death statistic of all players had been reset. So everyone was back and 0. I have backups so am trying to change it back for all 20 players.
For some reason when manually changing the death statistic in the stat folder (for each UUID) it somehow reverts back to the resetted value.

So for example. My death statistic was 130. It was reset to 0 and is currently back to 13.
I stop the server. Manually change the statistic in the .json file from 13 to 140.
I boot the server, 13 is back as statistic ingame and in the .json file.
Are the values backed up anywhere?

Only relevant plugin is WebStats (display stats on a webserver) but that doesn't change the stat file's, only reads them. I've deleted it database to confirm and it didn't change a thing.
I can't think of any other plugin that messes with statistics that I use. I also haven't changed or added any plugins recently that would incitate that.

If more information, like full plugin list or anything else is needed, let me know.
Any suggestions are welcome.


Thanks a lot in advance!
Werra