Radiator Leaking smoking question

[gotchu]

i had my koyo radiator fixed by a radiator specialist - expoxy on the bottom and top part..

so i got the radiator back and installed n bled..after the cap gets to operating temperature..i can start seeing white steaming coming out the rad and when the fan turns on coolant leaks on the bottom part..and when the fans not on it doesnot leak.

so today i took it out and we did a preasure test and smoke test with dye and no leak was found on the radiator which got me scratching my head..

any ideas whats wrong with the rad cuz im getting confused here lol thx in advance