I set it to 4 Kbytes/s and the average upload is 12 Kbytes/s
I assume it should be 4Kbytes/s total. (No other dowloading apps)

For a while there I thought I was beta testing
The bandwidth limit seemed to do the opposite of what
is was supposed to.
I set it to the max 12Kbytes/s and my download speeds all went
down. I set it back to various levels 10,8,6,4.
The result was that the lower I went the higher my download
speed.

Ok I then maxed out my connection with other downloads to
prove my isp was not limiting my download when upload levels
are high. I was able to achieve max download at the same time
as uploading.

I did this twice and then today the correlation is gone?

I find that I am consistently uploading way more than I am
able to download, even though I have lots in the queue and
my bandwidth is not fully utilized.
I have unchecked the max badwidth when away and yet when
I come back I find the upload at 16 Kbytes/s and the
downloads at ~4Kbytes/s or 0.
Once I am back my downloads improve