[CRASH] "Unable to connect to the server."

Details: I've received this error on 3 different occasions recently when trying to enter a League game (this time it's TFT, previous times it was ARAMs). The game hangs on a black screen (before any loading info shows up) and eventually a popup says "Unable to connect to the server. Please check your network connection and attempt to reconnect to your game." Clicking "retry" or exiting to client and clicking "reconnect" does not resolve the issue. After checking the logs I attempted to ping the provided IP address from the command line and it worked fine. And in between each occurrence I have been able to play several games without issue, so it doesn't seem to be a port or firewall issue. I even ran the Hextech Repair Tool to reinstall the client--no dice.

Steps to reproduce: Uncertain. Bug appears to happen randomly, but only as of the past week or two.

Relevant game log section:

000000.696| ALWAYS| CONN| Connecting to address (192.64.173.131) port (5353) 000000.702| ALWAYS| Waiting for response from server... 000001.060| ALWAYS| Waiting for client ID 000031.066| ERROR| Timeout waiting for server response. 000032.476| ERROR| User cancelled after timeout while waiting for client ID 000032.479| ALWAYS| {"exit_code":"EXITCODE_NONE","messageType":"riot__game_client__connection_info","message_body":"Game exited"}