I recently updated to Transmission 4.0.6 from 3.0.0, (running on Mac OS 12.7.5), and on the site I use most often, 30 of my torrents are showing up twice. A site admin told me this is because 4.x.x no longer supports the old way of sending both IPv4 and IPv6 addresses when announcing, and I should only announce IPv4 addresses. How do I change the settings in Transmission to do this? I suspect this is something simple and obvious, but I couldn't find it in the preferences, and I don't remember how this was set up originally!
ETA: I found my notes and it turns out in 2017 I turned off IPv6 for the whole computer by changing the TCP/IP settings in System Preferences for "Configure IPv6" to "Link-local only". It worked until this week, when I updated to Transmission 4.0.6, and I have no idea why it suddenly doesn't.