Help with audio volume in 4.11

I posted this issue a few days ago, but with no response. So, I’d thought I’d try again with more detail.

I have a blueprint that increases/decreases the exterior volume on an audio volume (depending on a door being opened or closed). It is working well in 4.10. I’ve opened the project in 4.11 and my setup is no longer working. Here’s the blueprint:


That said, I don’t think the blueprint is the problem. I’ve tried turning my exterior volume up in the ambient zone settings - I’m still not hearing any exterior sound when in the volume. So, I assume the issue is the new ‘LPF’ settings. It must be overriding my exterior volume settings. Problem is, I can’t find any info on the setting or how it should be set (or ignored!). Or whether I should be using it instead of ‘exterior volume’.

Any help would be appreciated getting this working again. Thanks!

EDIT: Actually, doesn’t seem to be LPF - whether I set it to 0 or 100000000 doesn’t seem to make a difference. I’m still getting no exterior sound at all.