SIM not being detected, LEDs don't light up

I am using a BPI R4 with a WIFI7 module and a Quectel RM520N-GL LTE modem. With the modem installed or disconnected, the SIM lights in all slots do not light up when there is a SIM inside. No matter what I do, it can’t seem to detect any SIM. I’ve already tried a few AT commands like mmcli -m 0 --command="AT+QSIMDET=0,0" and mmcli -m 0 --command="AT+QUIMSLOT=1" but nothing works. It’s currently in usbnet mode 2 which is MBIM but even in 0 (QMI) it doesn’t show up.

I’m on OpenWrt 25.12.0 and the modem firmware version is RM520NGLAAR03A03M4G

root@OpenWrt:~# mmcli -m any
  -----------------------------------
  General  |                    path: /org/freedesktop/ModemManager1/Modem/0
           |               device id: f7d33bde9ba12dbde9af3fe334a839611e2cd98b
  -----------------------------------
  Hardware |            manufacturer: Quectel
           |                   model: RM520N-GL
           |       firmware revision: RM520NGLAAR03A03M4G
           |          carrier config: Volte_OpenMkt-Commercial-CMCC
           | carrier config revision: 0A012010
           |            h/w revision: RM520N-GL
           |               supported: gsm-umts, lte, 5gnr
           |                 current: gsm-umts, lte, 5gnr
           |            equipment id: 868371056197219
  -----------------------------------
  System   |                  device: /sys/devices/platform/soc/11200000.usb/usb2/2-1/2-1.1
           |                 physdev: /sys/devices/platform/soc/11200000.usb/usb2/2-1/2-1.1
           |                 drivers: cdc_mbim, option1
           |                  plugin: quectel
           |            primary port: cdc-wdm0
           |                   ports: cdc-wdm0 (mbim), ttyUSB0 (ignored), ttyUSB1 (gps),
           |                          ttyUSB2 (at), ttyUSB3 (at), wwan0 (net)
  -----------------------------------
  Status   |                   state: failed
           |           failed reason: sim-missing
           |             power state: on
  -----------------------------------
  Modes    |               supported: allowed: 3g; preferred: none
           |                          allowed: 4g; preferred: none
           |                          allowed: 3g, 4g; preferred: 4g
           |                          allowed: 3g, 4g; preferred: 3g
           |                          allowed: 5g; preferred: none
           |                          allowed: 4g, 5g; preferred: 5g
           |                          allowed: 4g, 5g; preferred: 4g
           |                          allowed: 3g, 5g; preferred: 5g
           |                          allowed: 3g, 5g; preferred: 3g
           |                          allowed: 3g, 4g, 5g; preferred: 5g
           |                          allowed: 3g, 4g, 5g; preferred: 4g
           |                          allowed: 3g, 4g, 5g; preferred: 3g
           |                 current: allowed: 3g, 4g, 5g; preferred: 5g
  -----------------------------------
  Bands    |               supported: utran-1, utran-4, utran-6, utran-5, utran-8, utran-2,
           |                          eutran-1, eutran-2, eutran-3, eutran-4, eutran-5, eutran-7, eutran-8,
           |                          eutran-12, eutran-13, eutran-14, eutran-17, eutran-18, eutran-19,
           |                          eutran-20, eutran-25, eutran-26, eutran-28, eutran-29, eutran-30,
           |                          eutran-32, eutran-34, eutran-38, eutran-39, eutran-40, eutran-41,
           |                          eutran-42, eutran-43, eutran-46, eutran-48, eutran-66, eutran-71,
           |                          utran-19, ngran-1, ngran-2, ngran-3, ngran-5, ngran-7, ngran-8,
           |                          ngran-12, ngran-13, ngran-14, ngran-18, ngran-20, ngran-25, ngran-26,
           |                          ngran-28, ngran-29, ngran-30, ngran-38, ngran-40, ngran-41, ngran-48,
           |                          ngran-66, ngran-70, ngran-71, ngran-75, ngran-76, ngran-77, ngran-78,
           |                          ngran-79
           |                 current: utran-1, utran-4, utran-5, utran-8, utran-2, eutran-1,
           |                          eutran-2, eutran-3, eutran-4, eutran-5, eutran-7, eutran-8,
           |                          eutran-12, eutran-13, eutran-14, eutran-17, eutran-18, eutran-19,
           |                          eutran-20, eutran-25, eutran-26, eutran-28, eutran-29, eutran-30,
           |                          eutran-32, eutran-34, eutran-38, eutran-39, eutran-40, eutran-41,
           |                          eutran-42, eutran-43, eutran-46, eutran-48, eutran-66, eutran-71,
           |                          utran-19, ngran-1, ngran-2, ngran-3, ngran-5, ngran-7, ngran-8,
           |                          ngran-12, ngran-13, ngran-14, ngran-18, ngran-20, ngran-25, ngran-26,
           |                          ngran-28, ngran-29, ngran-30, ngran-38, ngran-40, ngran-41, ngran-48,
           |                          ngran-66, ngran-70, ngran-71, ngran-75, ngran-76, ngran-77, ngran-78,
           |                          ngran-79
  -----------------------------------
  IP       |               supported: ipv4, ipv6, ipv4v6
  -----------------------------------
  3GPP     |                    imei: 868371056197219
  -----------------------------------
  SIM      |          sim slot paths: slot 1: none (active)
           |                          slot 2: none

There’s a post here about someone whose card slot is broken and they can’t use the card. I think you might have the same problem.