What gameplay feature is this bug affecting?
Battle Arena/Tournaments

What's the issue? Please include any error messages you receive and as much detail as possible.
My king just won two rounds in a row in the tournament, each win had 5 MB, but I only ended up with 9 MB. I was at 0 MB when I entered the round.
My user log says I won 4 MB in the second round.

Any links relating to this bug? For example, if a particular lion is bugging, what is the link to that lion?
https://www.lioden.com/may_challenges_tournament.php?id=196178

Any screenshots you can provide us with?
https://imgur.com/2R3g8Pm

Please provide us with step by step explanation how this bug happened so we can attempt to replicate it. If it's complex, please include screenshots where possible:
I entered the arena with 0 MB
Clicked away from the site
Checked inbox and followed the link to results
won two rounds of the tournament, lost the third one