One of my users is reporting an inability to connect to ircs:// with mIRC v7.66. They report that initially they were able to connect, but then a subsequent connection attempt failed. This suggests a possible issue with STS, since the server publishes the following STS token in its CAP LS 302 output: "sts=duration=86400,port=6697".

Here's the client configuration:

The error is: "[05:24pm] * Unable to connect to server (SSL certificate verify failed)". (The time is 5:24 PM PDT [UTC-7] on September 29th, 2021.)

Here is the current certificate chain we are serving:

Thanks very much for your time.

Co-maintainer of the Oragono IRC server