TOP247YN, issues

hi,

please find attached the schematic and transformer design for TOP247YN, 4V/15A

power supply,

there is a failure of TVS Diode under very light load and under the no load ,

the p6ke200a diode heats up,i feel there is a problem with clamp section and the schematic,

please help in selecting the x pin resistor value,

please comment on the transformer design,

please help in this regards,