The Dialogs Are Auto-Dismissed Running Sample Scripts In Script Editor

macOS Mojave
AppleScript 2.7
ScriptEditor 2.11
Dialog Toolkit Plus 1.1.2

I run the script, the dialog flashes before disappearing. I have to run repeatedly until it’s stuck. It’s the same in every sample script. Why is it so?

What happens if you use Script Debugger?

It ran as expected but in ScriptEditor the button giving up would go off arbitrarily and before long when the time allotted for the action to fire up hasn’t elapsed: now the dialog stays put, then it doesn’t.