Over the days on debugging, I reproduced this for a couple of methods if those get called in the Open event. Please note the Open event is run before the control is constructed in the browser, while the Shown event is run after its creation.
To Identity possible cases, we when through controls and set hundreds of properties and called hundreds of methods to figure out possible candidates. Later we search those in our big project to check if one of our bug reports is caused in such a way. I got this list of candidates:
- WebControl.ContextualMenu property
- WebTextArea.ScrollPosition property
By the way for Web 2 the Xojo engineers put in a lot of effort to eliminate this problem. Let us know if you find the same problem in Web 2 somewhere or more cases in Web 1 where it happens.