That sounds like you ran into a connection issue during Champ Select. Do you ever experience lag spikes or packet loss during your games, such as rubber banding or a momentary inability to take actions even if the rest of the game is continuing properly around you?
You can check for latency or packet loss by downloading the WinMTR Network Diagnostic Tool, then use that to run a traceroute to the following IP for NA (allow this to run for 5-15 minutes);
104.160.131.1
The Connection Troubleshooting Guide may be able to help, and if you need assistance post on the Help & Support board. If you can't find any connection issues it may have been temporary, but you can post on that board for their assistance either way.
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