Thanks Paul. This was a bug in the runtime’s resize-lock initialisation.
When a saved window size was restored before the window appeared, the runtime incorrectly treated that restored size as the original layout size. The container still had its designer width, so there was no calculated width change for the right lock to apply. A smaller window concealed the problem by clipping the oversized control.
This is now fixed. Resize locks use the visual designer dimensions as their baseline, then correctly stretch or shrink controls when the saved window size is restored. Subsequent manual resizing also continues to work normally.
The fix will be included in the next release: https://feedback.objo.dev/bug/1295
Thanks for reporting it!