Reason I'm posting back? My (non-clicking system) in Studio One also shows that 32 bit depth. It's bit depth, not sample size and it's to do with the internal engine on Studio One I believe. I cannot actually seem to change this from 32 on my system. Thought I'd mention that before the OP spends hours trying to figure out how to turn that off!!
If you click on the Song setup" button, you can change the bit depth for the particular project. My default is set at 24 bits, even if the one under the preferences (as shown in the screenshot above) is set to 32 bits ( which I assume is for the internal mix engine).
Something to check at least