Hey there as a friendly reminder, all disconnections and game crashes counts as leaving the match and will be penalized appropriately. The game server has no way to discern a legitimate disconnection or game crash from one that is forcefully caused by a dishonest player to bypass leaver penalties. You can learn about this policy here:
There was some issues that was causing disconnections for some players earlier but have since been resolved. I recommend playing several games in a non-competitive mode to ensure there are no more issues for either of you. Otherwise be sure to follow basic connection troubleshooting or reply if you need more help.