Match was not counted. (Client)

So i'm not sure exactly what kind of bug you'd consider this, but a ranked 5s match doesn't show up on my, or my teammates match history on the league of legends client (or on lolking.net), and it appears to not have counted towards our wins either (we gained 0 LP from winning). However, it does show up on op.gg match history, and also on the online LoL match history.

If it counts for anything, none of us got a bug splat. But we did all have the "Waiting for stats..." screen. Some of us clicked to skip it because it was taking a long time, one of us just had it eventually close itself without clicking the prompt.

Fortunately (or unfortunately, in regards to debugging), we have only had this occur once so I have no idea how it might be reproduced.

Attached is an image of client history and op.gg history