I think you are trying to describe the latency you are experiencing (the delay between the input source and when you actually hear it through the monitors/headphones).
In Studio One there are two pages where you configure audio processing.
It sounds like you found the first one and set the "device block size". I'm guessing that you set it to 32 or 64.
Now switch to the Processing tab and change the Dropout Protection to Minimum.
This will provide the lowest level of latency.
I think you also want to check "Use native low latency monitoring instead of hardware monitoring.".
For more information, go to the Help menu and select Studio One Reference Manual
Expand the Recording section and see the "Cue Mixes and Low-latency monitoring" section.
BTW, I also moved to Studio One when SONAR was abandoned.
It has since then been picked up by Bandlab and continues to be maintained and improved.
It is free.