The control app is not involved in Background Analysis at all. It happens completely on the server.
It’s worth checking to make sure that your audio analysis speeds are set to “fast”. We default them to a throttled setting to avoid triggering CPU fans. This uses about 30% of one CPU core. If you turn it up to fast it will use a full CPU core In the future we will probably provide options to parallelize analysis across multiple CPUs, but that is not there right now.
If that doesn’t help, flag @eric and he will help you troubleshoot.