[2024-10-02 11:11:26:575_S:] AT+QFUPL=“UFS:AmazonRootCA1.pem”,1187
[2024-10-02 11:11:26:634_R:] AT+QFUPL=“UFS:AmazonRootCA1.pem”,1187
[2024-10-02 11:11:26:634_R:] CONNECT
[2024-10-02 11:11:28:260_S:] AmazonRootCA1.pem
[2024-10-02 11:11:33:309_R:] +QFUPL: 19,1765
[2024-10-02 11:11:33:309_R:] +CME ERROR: 421
why am getting error