Flyback power supply voltage rise during light load

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We are using Top 265 EG in one of our power supply design, the power supply specifications are listed below

Input: Universal input 85-264V AC
Device: TOP265EG
Type: Flyback
Output 1 :24V rated for 0.6A
Output 2: 5V rated for 1.25A
Secondary winding: AC stack(24v on top of 5V)
Feedback: Weighted feedback Optocoupled using TL431

we have designed the prototype and both power rails (24V & 5V ) are fine during the no-load condition, but when 5V rail is lightly loaded (say 10mA), the 24 V rail shoots to overcome this issue, we added a preload of 20mA to the 24V rail and the voltage rise came down to 25V and load& line regulation was found to be ok

is there a way to avoid this preload to reduce the power consumption during no-load condition?
Kindly suggest??

It is a cross regulation issue. Please share schematic and transformer datasheet.