Media Grid Plugin Isssue

Hello Everyone,
I’m having some weird issue with the Media Grid Plugin.
Under the Grid builder option where we need to select Item categories and we define what goes where and their sizes of the display.

All that is done and sizes have been defined accordingly. When i preview it shows exactly how i want it to be but when i’m clicking on some other option on the same page and switching back to the old one the layout / placement of the Sub-categories change.
Supposedly i have set two Item categories side by side at 1/2 by 1/2 (both are same sizes) – when i preview the same they’re exactly how we want it but whenever i click on some other tab in the same page and get back to the former the two categories are not side by side anymore – they’re one below the other now.
Can’t find the root cause.
Any help would be much appreciated.