Okay awesome, thanks for reporting this. There's seems to be a bug in Windows where going in and out of the altscreen will incorrectly fire off a WindowResizeMsg. This wasn't the case in prior versions of Bubble Tea because resize events weren't possible.

In your case the flickering is happening because of this line, which seems to have been left in by mistake:

diff --git a/client/main.go b/client/main.go
index b8fe61a..37b8bd7 100644
--- a/client/main.go
+++ b/client/main.go
@@ -246,7 +246,6 @@ func (m model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 			m.input.Reset()
 		}
 	case tea.WindowSizeMsg:
-		clCmd = tea.Sequence(tea.ExitAltScreen, tea.EnterAltScreen)
 		m.history.Height = msg.Height - 2
 		m.history.Width = msg.Width
 		m.history.GotoBottom()

Of course, WindowSizeMsgs shouldn't be fired off at all during altscreen toggles, so we'll also make the corrections in Bubble Tea.

🤦 I just have to say thank you so much for digging through and noticing what was wrong with my code.

Yes that was left in, from a previous attempt where I thought maybe exiting and re-entering altscreen would cause new Height/Width values to be used.

Just tested removing the line and yep, works exactly as expected, including resizing! ❤️