Nureva HDL300 Dual Sound Problems

I have a client that is using a dual Nureva HDL300 system. We have installed these multiple times, never with any  complaints for a Zoom Rooms conferencing centre/boardroom. This system however from the offset has poor audio quality and comes out sounding as if you are underwater!

So far, we've recalibrated the bars and they work perfectly with MY Zoom credentials. 

This is not a clear fix, however one troubleshooting option is on the Zoom settings themselves. Changing them, turning them off due to conflicting with the HDLs defaults maybe?

Has anyone else come across this problem?

Thanks!