Hi Gil,

Thank you very much for reporting the behavior. 

There is already logged related issue in our Feedback Portal. Below you will find a link to the item:

- https://feedback.telerik.com/aspnet-core-ui/1626545-the-pagesizes-option-is-hidden-when-the-grid-initializes-inside-a-hidden-container

In the item there is also a suggested workaround:

grid.pager._lastWidth = 30;
grid.resize(true);

I modified the provided Dojo example with the suggested workaround and linked here you will find the example containing the workaround - https://dojo.telerik.com/@NeliKondova/aLilOXum

In addition, I am posting a link to the related GutHub issue. As you can see in the item the bug fix is currently 'Ready for Test':

- https://github.com/telerik/kendo-ui-core/issues/7545

Still, the issue does not have a milestone set. Once the issue passes the needed tests it will also have marked milestone.

With the above said I will mark the current report as Duplicated. I have also added the example from your report in the issue in GitHub in order to describe the scenario.

I remain at your disposal in case you have any additional question on the matter.

Regards,
Neli
Progress Telerik