The amount of Diffuse, Glossy and Transmission are bound by the Total Max Bounces, so in above setup there will only be 8 Diffuse bounces (actually 9 because Blender starts counting at 0…).
When you set the Transparency above to 16 Bounces there will be 16 (read 17), not 8 (read 9). Similar with the Volume.
Bit confusing, I agree…
