Illustrator outer glow showing in CS6-exported PNG but not CC2019-exported PNG

Hello!

I have a stack of illustrator files (.ai) with the Outer Glow effect applied, all placed in layers in Indesign. When I run off a given PNG in CS6 it comes out as expected. But when I run off the same image in the same file in CC2019, I only get the line art, none of my glow effects are included in the output PNG. Weird?
Yes... I could just export my PNGs in InDesign CS6 (or illustrator itself) but have found a helpful InDesign script which will export all my layers for me (I have more than 50) as individual PNGs - but the script only works in 2019 or higher! 
Is this known/fixable or will I have to do them all (one at a time) in the older software?

I really appreciate any help you can offer!