So in following the tutorial, I'm doing a simple dummy custom Bottom Panel plugin, whose GUI only has a Button labelled "Click Me" with its pressed signal connected to a func that simply prints.
Specifically, that GUI (which does show up in the Editor as a Bottom Panel!) has _ready and _enter_tree both do a print that never shows up anywhere, and has its Button node's pressed signal connected to 2 funcs: one is connected programmatically in _ready and the other declaratively in the gui.tscn (ie. interactively via Godot Editor's Node/Signals dock). Both do first a print and then an EditorInterface.popup_node_selector call, just to see some onclick action here. All these funcs aren't ever called at my end. Including after project-reloading, editor-restarting, plugin-disabling-and-re-enabling etcpp.
So somehow I only succeeded in showing a Bottom Panel label/tab "Dummy Plugin" that upon selection shows my single-button GUI. But the script code attached to that GUI scene just isn't ever running. No error/warning messages anywhere either.
What am I missing in my minimalistic dummy project? Minimal repro project: source code here, ZIP'd here
This is Godot 4.3-4 on an Arch Linux system.