I had similar issues on an iPad 2 and an iPhone 5s. Both on most recent iOS 9.
I replaced almost all tables with newer containers and took out all conditional visibility. To conditionally display elements I used my css selector helper widget and css. Apparently safari likes css selection far better than dynamically inserting and removing chunks of html.
Also denormalized some read-only data to reduce number of requests and simplify the design.
No more random vanishing and the application performs much better too.
edit: This happened not only with safari but also in the Mendix developer app
It seems that this issue is introduced with the new UI framework. I have experienced the same issue in multiple projects. It seems that this issue is triggered by styling. When I deploy the app using custom stying, the page turns blank after you try to scroll the page when the server has sent validation feedback to the client.
We have tried several things and one thing that 'worked', was to use the blank theme styling based on the new UI framework. With this styling, the same sequence of steps does not lead to a blank page. Perhaps you can try the blank theme and see if the issue persists?
I did not have had enough time to replicate this issue in a new project, but it seems that it is the combination between the page and the custom styling, which is still odd.
I think I have seen a similar issue. I believe the issue is down to the toggle button and the way the side panel slides over. Change the slide panel behaviour to something other than the default and this should fix the issue. It seems that the css in the side panel causes some issues with scrolling.
Mendix 5.21.2 and 6.3.0 both contain a fix to work around a bug in Safari on iOS, which causes content to disappear when scrolling. 5.21.2 is expected to be released today. 5.6.0 is expected to be released on February 29th. Could you please test whether this fix also solves your issues with scrolling on iOS?
I have seen this behaviour in older iPhones. The 4 would not show while a 4s would show the page. Could be an iOS specific problem. We have not investigated this further.
I think this issue is related to Mx5.20. Our project works fine on Mx5.17. After migration to Mx 5.20 we have the same slow experience . Tested on iPhone 6 with most recent iOS 9 using the Mendix developer app.
I've created a new project to reproduce the error, and sent the project file to mendix support. So far it seems that the issue does not occur when you're using a microflow button in asynchronous mode. Hope this helps.
So we just bumped our app up to 6.2.0 and now we have the same issues happening again, only worse. Also, a bunch of styling seems to be rendering improperly with 6.2.0. Anyone else having this problem?
6.3.0 appears to have fixed all of these issues. Thanks!