One of my recent games let me with a strange bonus pool. I fully believe this is some sort of glitch. But I was given a negative 3 Bonus pool after my 3v3 team was promoted to a new league. 
![enter image description here][1]
So... is it possible to get a negative bonus pool? Or is this a glitch?


  [1]: https://i.sstatic.net/Wtva8.jpg