Just curious, is this a non-Production environment? Before making any changes probably not a bad idea to take a backup. Not sure if this is a fresh install but with newer versions of Tableau Server the number of components are selected based on the underlying hardware resources. If for example an environment is at the "bare minimum" to run Tableau Server there will typically be just at most "1" of each process. I'd be curious if you ran the "tabadmin config" which should try to force configuration changes down to the YML Settings files. Though it's possible it might throw an error at that point. You could even try to change the value from say "4" to "3" and again see if it reveals any message that might account for the issue.
Based on my recent experience with Backgrounders this is conceivable. Also, isn't it recommended that there be one Cache Server per VizQL Server? Anyway...given the small values in the configuration I'm guessing this is a small server that has the minimum required hardware, thus the Tableau Server software is enforcing the use of default values. Just because you can make a value higher doesn't mean Tableau Server will actually follow your instructions!
Configuration is 96 GB memory - 24 Cores CPU. I thought this is enough?