This is not the library. Discord has a delay, to give a chance for reconnect.
Side-effect of #330
This does _not_ appear to be a side-effect of #330, although still a bug nonetheless.
Currently working on a solution.
Resolved as of 58291f819968aee84e3c13114620f55f520577f4
This is an issue again as of the recent changes to connection logic, needs more investigation.
This seems like a bug in .NET Core's ClientWebSocket, we still need to do some more research into that and submit a formal bug report.
For now, I've been able to send a proper close code through the WS4Net Provider, but not through the default provider.
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Side-effect of #330