Fullscreen issue with ionic framework

I have ionic/angular application and I am using gantt in it. The fullscreen plugin does not seem to work (displays black screen). I have tracked the issue to styles applied by ionic framework to pages on app. The app root and page that contains gantt has this class applied:
.ion-page {
left: 0;
right: 0;
top: 0;
bottom: 0;
display: flex;
position: absolute;
flex-direction: column;
justify-content: space-between;
contain: layout size style;
overflow: hidden;
z-index: 0;
}
Once fullscreen is enabled removing the display flex from the class shows gantt on fullscreen correctly.

However if I have some div and use element.requestFullscreen() it displays the div on fullscreen correctly. So is this some bug with the fullscreen plugin?

Hello Juuso,
I was able to reproduce the issue if Gantt is located inside an element with the fixed sizes:
http://snippet.dhtmlx.com/5/429acf9c8
In that case, you need to specify that this element is the root element that should be expanded to the fullscreen mode:
https://docs.dhtmlx.com/gantt/desktop__fullscreen_mode.html#ganttwiththeheadertoolbarinthefullscreen
Here is the snippet that demonstrates how it works:
http://snippet.dhtmlx.com/5/9d30daf41

If that doesn’t help you, please send me a ready demo that I can run so that I can reproduce the use case and check if there is something wrong.