Keep the aspect ratio of symbols inside a symbol while a browser is scaled up/down.

I'm struggling with a way to keep the aspect ratio of symbols inside a symbol (as the browser is being changed in size)

1920x1080 project. The screen is one symbol (1920x1080) with 16 split pieces (4x4 pieces 480x270 px) symbols inside.

But I cannot make it so they stay in ASPECT RATIO. Instead they either seperate or get squeezed when the browser get too short or tall.

I can do this will one single picture no problem. But because it's a symbol with seperate symbols inside,.. it doesn't work. Can't lock the

aspect ratio and have the browser just cut the whole image or add more background. Instead it squeezes or seperates the symbols.

Anyway to do this? Appeciate any thoughts/help.