Pressure theory is interesting, but everything is stock. I'll check the "radiator cap" and see if it is not to spec. I've been reading about hoses, and what I've found is that most hoses will slightly collapse under the clamping force. This makes sense as most materials creep when stress is applied. The collapse of the material then will reduce the stress (pressure) of the clamp. Some hoses will "stick" to the tube, and the collapse does not cause a leak. But, if the hose doesn't bond, you might get a leak, and the remedy is to tighten the clamp again.
Interestingly, silicone hoses don't "glue", making them more likely to leak, but easy to get off.
Also, interestingly, the stock clamps are "constant pressure" clamps, meaning even as the hose collapses, the pressure is maintained by the spring of the clamp. My aftermarket clamps are not constant pressure. I'll keep working this until I get it fixed.