Numerous disconnections, errors, game closures while in battle. It leads to losing a round or simply losing the battle because match ended for some reason or a turn was skipped.
Timer expiration after around 5 seconds of your turn when you are able to play cards in your hands.
After attempting to block attacks from 2 enemy creatures, I was able to select which attack to block with both of my creatures but nothing happened, timer expired and both attacks hit my planewalker.
Disconnection when card "poxbug plague" was used.
Lag... So much lag...
It sounds like you may need some more troubleshooting advice, please submit at: https://magicspellslingers-support.wizards.com/hc/en-us/requests/new and select 'Technical Troubleshooting'.