We are on APEX 21.2 locally. I have tested this on the latest version of APEX via apex.oracle.com and this same behavior happens there as well.
I have four classic reports within an RDS region all with “Lazy Loading” set to “on.” These reports and RDS region are on a page that is defined as a modal. When the modal opens and the user clicks the RDS tab the reports are in, only two of the reports load lazily. The other two do not load at all. If the user clicks to another RDS region and then back again to the one containing the reports, a third report then loads lazily. Repeat again for the fourth classic report to load lazily.
This same behavior happens when the page is defined as a non-modal page. This behavior does not happen on a normal page.
This same behavior happens when the RDS is changed to tabs.
I have set up an example on apex.oracle.com for people to see the behavior demonstrated:
https://apex.oracle.com/pls/apex/r/baconlovers/playground/home
I have not tried to turn the classic reports into interactive reports or read-only interactive grids to see if the same behavior happens.
Any suggestions or help would be greatly appreciated. I am leaning toward this being a bug in the APEX engine but am happy to learn I set something up wrong as well.
I can provide an export of the app or developer credentials to the app upon request.
Shane.