AdiIRC

Note: I frequently use Window>Minimize/Hide All Windows and get this weird behaviour. After a lot of trial and error, I think I have a solid repro.

1. Open up AdiIRC.
2. Connect to a server and join at least 3 channels, autojoin is fine or you can do it yourself. For example, join #test1,#test2,#test3.
3. Choose the Window menu and choose Minimize/Hide All Windows.
4. Using either the Treebar and Switchbar, select the 2nd last channel, and then the first channel. For example, click on #test2, then #test1.
5. Then choose the 2nd last one again and the third one. For example, #test2, and finally #test3.

The last channel will now not be in focus, although the textbox in the window will be. The Treebar and Switchbar will report that you are still looking at the 2nd last channel (#test2). If you send a message to the channel, it will appear as though there was a new message (red coloured). If you maximize the channel window, it will not integrate itself into the main window as the normal MDI windows do and instead maximize itself with its own titlebar in the workspace.

As a workaround when this happens, you can choose Minimize/Hide All Windows again and then select the broken channel, which will now come into focus.

Tested on both 2.3 and 2.4 beta, both on Windows 10 and Windows 7.

I attached a quick video demo to show this, the effects and then showing the workaround.