It could be either the hose is faulty or the bottom radiator tube connection may have "spider-cracks" which means you'll need a replacement radiator.

I would not over-torque the clamp... maybe add a second clamp on the edge of the rubber hose near the radiator itself.

With a 2nd clamp attached, might be enough for now to stop your leak.

 

Look at the PIC. If you put another clamp inboard you will then clamp on the stand that tells you where to put the hose up to. if you compress that stand you will for sure push it right through the rest of the nipple wall and ruined radiator. If anything loosen first clamp and put the edge dead even with end edge of hose thus giving enough room to put a second clamp on behind it.

The old hose often cooks from heat to almost become part of the plastic, if that happened and you leave a bit of hose remains on the nipple then you get leaks like that too.

As mentioned the plastic used there with age begins to crack all over to make minute leaks, Ford gave a substandard part there that will not last the life of a normal car. It has the same problem as the zetec stat housings do, made of an inferior material to make the cars go to the crusher faster.

 

............

As mentioned the plastic used there with age begins to crack all over to make minute leaks, Ford gave a substandard part there that will not last the life of a normal car. It has the same problem as the zetec stat housings do, made of an inferior material to make the cars go to the crusher faster.

Not knowing what year OP's Focus is-
I'm shocked it lasted this long down there in Mexico...

Some time around '12 or '13: My Uncle in Mexico picked up an '02 Mach Edition Focus Sedan w/ less than 100k miles & spent it's entire life in SoCal and had zero issues.

Due to the heat/humidity of the tropics in Mexico and poor road conditions; That Focus didn't survive two years down there before he had to get rid of it before it caused him more problems.