I have been on 5.9.1.6 (tried 5.9.2.3 but did not work well with alert playbacks).

I am now testing 5.9.3.0 and when I double-click on an alert in the confirmed alert list then Blue Iris jumps to the correct position but playback does not start.
Clicking on playback / speed icon does not help either.
However, moving the time line to the alert (while in real time mode) and then double clicking on the time line where the alert is tagged works fine.

I will report this to Ken in email.

Ooh, v5.9.3.1 just arrived. That usually means there was an issue with the previous version. Updating...

And yes, v5.9.3.0 did do as you said, and v5.9.3.1 is working here. I had only tested v5.9.3.0 remotely with UI3 and it was OK there.

He he I just got a reply back from Ken and he told me had released 5.9.3.1 that fixed the issue and I can confirm that it works now.