Canvas, stage and sprites relationship

Does documentation exist that explains the relationship between canvas, stage and sprites?
My problem: I am converting a project from Classic, and I do not fully understand the functionality of a “stage”. The stage comes with the canvas automatically it seems, and I don’t know what to do with it.

Hey Luc,

According to the docs the stage allows you to set the background colour of your game.

What sort of game are you trying to convert?

Tnx for the prompt reply! My project is not a game, but a “glass cockpit” instrument landing system, GPS based, that can be used in either real or simulated flight, on any airport in the world, whether or not that airport is equipped for instrument landings. The Classic version is almost complete and in the process of converting to X. I have already tested the app in real life, on small airfields as well as large international airports.
Feel free to have a look at my public project “Stage issue” where I demonstrate the issue: on startup, the preview most closely represents the intended design, whereas the representation on IOS as well as on Android is wrong and not what I intended. Never mind the blocks, even at startup the differences are demonstrated.

Hey @Luc, what does “on startup” mean in this context? Do you mean the phone preview in the Thunkable designer?

Thanks

Startup means: image
where variables are initialized. Just in case you didn’t have a chance to look at the screen outputs, here they are:
1- PC screen preview: image
2- Android:


3- IOS:
The position of the gr-red-bl bar is irrelevant, but the position of the green “stage” square is ok in (1) but positions partly outside of the cancas in Android as well as in IOS.

This is the simplest representation of my problem: why does the stage (green square) not center on the canvas? Margin and Padding of Canvas is all zero’s. The screenshot of the output is on an iPhone 6S IOS 13.3.1