Dear Wannipa san,
I am sorry for trouble you for this problem.
Now BSSS is still investigating for this matter. BSSS recheck the production history found that at the same time 7 products produced by the same machine. 7 products were in the same lot and same pack. 7 products have already used in BTMT by the same time only 1 product had problem. The presumption cause is following two reason.
1. During take-off operation, the cord cross may happened when the cord split check. For this presumption cause BSSS is making verification test.
2. Product spool deformation. the abnormal product will arrival BSSS next week and we will check the situation of the spool.
Before the root cause find out, as an interim countermeasure BSSS recheck the surface for each product before the shipment to prevent the cross happened. BSSS is still investigating for this matter and the investigation report will send to BTMT in 3/25.
Best regards,
BSSS Di Guofeng