TPS82140: Possibility of reason for damage

I investigating about the reason of damage for a few TPS82140 and TPS82150.

Customer condition is below;

・Schematic is based on EVM with adjustment Rfb.

・Vout have many case: 1.2V~5V, these are also damaged.

・Iout is smaller than Module's current limit (TPS82140: 1.2A, TPS82150: 0.9A)

・Startup have enough margin for the two case: Reset IC to EN (about 400ms delay), or long soft start time (50ms)

・Input side is connected AC/DC module: CLP0212FPEX5Z01C

【Question】

・Are these condition require TVS or Fuse on input side of TPS82140/50?

・When hand operated switch ON ⇒ OFF ⇒ON (less than 1sec), is there possibility to damage?

・If there the other reason for damage, please let me know.

Best regards,

Satoshi