Hi,
Thank you for all the information.
Are you able to reproduce the issue in a simple test map? Or is it only happening when in your specific game situation.
It could be an issue with the attenuation position. Another forum discussing a similar issue can be found here: Attenuation on Character, Spatialization on the Camera -- UE5.1 - Fmod Studio 2.02.11.
Just to confirm, the original version was 2.02.18?