Hi Easy peasy and Andrew,
Thanks so much for your replies, I gotthe transformer recommended in the application circuit WURTH 750315126, I checked my power supply directly with a load (can source up to 5 Amps without problems). Andrew, thanks so much for your simulation!! I changed the Rload to 12 ohms and shows that it should deliver 1A (attached).
I checked again and again and I still can figure out why the circuit can't deliver current, I replaced the LT8304 but still the same problem, the circuit has only a few components so I don't know what to revise now - all the components are the ones recommended on the datasheet. Today I run a new test,I changed the transformer for a 24V ( WURTH 750315836), following the circuit on the datasheet( components don't change as the Vout depends on transformer ratio that changes to 1:1), I got the same problem, output voltage is ok but when I connect any load (2k resistor)the voltage goes down.
Any ideas of what could be wrong? since the circuit is so simple i feel that I'm missing something silly...?