I have been noticing this since a while , when reset happens my beast at lvl 3 castles show 5k + ( depending on beast level ) , but I always get less than -5.0k . Thought it was my bad memory in the begining till I did a screenrecord https://youtu.be/r1ZSPztMRK8 . Wrote to support they admit the team saw this bug.
As far as I can remember this thing is not working since weeks , @Arelyna I am putting this here with the hope that you will buzz someone and have an update soon . I would hate to see shards being lost especially where there is not many of those and I hope you guys prioritize this