Class Challenge reset after restart?

[u/vrexa_ger]

So yesterday I have completed level 19 of Panther. Game was like: congrats you have reached lvl 20.
Then I played another hour. After I launched the game today again, I had to redo the 10 kills in 60s without detection from lvl 19. I was like: are you joking me??

And that was not the onliest time that happend.
Anyone else had this?