Thanks for the pics!
First pic is your upper coolant reservoir, and that's not an OEM one.
3 and 4 pics are your Intake cam ACVS solenoid (variable valve/cam timing) and that banjo bolt is connecting to an oil line/gallery. Don't think the leak is from that, as it'd be an oil leak not a water leak.
I'd focus on checking the clamps, hoses and barbs of the upper reservoir.
Also, how is the tube plumbed into the overflow bottle?

