[Electronic Circuit] Found defective products after 100 boards were installed and filed a Quality Complaint with JLCPCB.
The order was placed with JLCPCB for 100 boards, but in reality some of the pin headers were slightly out of level, resulting in LCD displays interfering with each other and not fitting together The JLCPCB order history section has a 'Quality Complaint' field where you can enter the nature of the fault and the number of faulty boards. and the number of defective boards.