Gameplay, TFT, unsellable spider

After a round, a spider ended the round while on my bench. Once I warped back to my arena the spider took up a unit slot on my bench.

https://cdn.discordapp.com/attachments/320011173539872780/596916758548447242/unknown.png

I tried selling it for the 0 gold listed to remove it... aaaaaand

https://cdn.discordapp.com/attachments/320011173539872780/596916908763381760/unknown.png

The number 429467294 appeared over my gold amount and the spider was still on my bench. It remained there for the remainder of the round as an unsellable unit.