Hi there,
I simulate your question, I think its related with popup resizing.
İf you say resizable to no it works as u said. You can change it to resizable to yes and adjust custom height etc.
Hi Bosung,
Please refer the below similar communication,
https://community.mendix.com/link/space/ui-&-front-end/questions/122884
Hope it helps!
Thanks & Regards,
Manikandan K