Unknown error (NEGOTIATION_FAILED) Unknown error (unsupported method)

Using modem manager with Quectel rm520n-gl with firstnet. Modem initially connects and registers with network then immediately disconnects. Perplexed as to why, here are the last couple lines of the log. Tried searching the forums but could not relate. Thanks

Fri Jun 14 17:26:31 2024 daemon.notice netifd: Quectel (13205): successfully connected the modem
Fri Jun 14 17:26:31 2024 daemon.notice netifd: Quectel (13205): signal refresh rate is not set
Fri Jun 14 17:26:31 2024 daemon.notice netifd: Quectel (13205): network operator name: FirstNet
Fri Jun 14 17:26:31 2024 daemon.notice netifd: Quectel (13205): network operator MCCMNC: 313100
Fri Jun 14 17:26:31 2024 daemon.notice netifd: Quectel (13205): registration type: home
Fri Jun 14 17:26:31 2024 daemon.notice netifd: Quectel (13205): access technology: lte
Fri Jun 14 17:26:31 2024 daemon.notice netifd: Quectel (13205): signal quality: 0%
Fri Jun 14 17:26:31 2024 daemon.notice netifd: Quectel (13205): IPv4 connection setup required in interface Quectel: ppp
Fri Jun 14 17:26:31 2024 daemon.notice netifd: Quectel (13205): IPv6 connection setup required in interface Quectel: ppp
Fri Jun 14 17:26:31 2024 daemon.notice pppd[13307]: pppd 2.4.9 started by root, uid 0
Fri Jun 14 17:26:31 2024 daemon.info pppd[13307]: Using interface ppp0
Fri Jun 14 17:26:31 2024 daemon.notice pppd[13307]: Connect: ppp0 <--> /dev/ttyUSB2
Fri Jun 14 17:26:31 2024 daemon.info ModemManager[13310]: hotplug: add network interface ppp0: event processed
Fri Jun 14 17:26:31 2024 daemon.debug ModemManager[13310]: hotplug: sysfspath is a virtual device (/sys/devices/virtual/net/ppp0)
Fri Jun 14 17:26:31 2024 daemon.notice pppd[13307]: Modem hangup
Fri Jun 14 17:26:31 2024 daemon.notice pppd[13307]: Connection terminated.
Fri Jun 14 17:26:31 2024 daemon.info ModemManager[13335]: hotplug: remove network interface ppp0: event processed
Fri Jun 14 17:26:31 2024 daemon.debug ModemManager[13335]: hotplug: sysfspath is a virtual device (/sys/devices/virtual/net/ppp0)
Fri Jun 14 17:26:32 2024 daemon.warn odhcpd[1716]: No default route present, overriding ra_lifetime!
Fri Jun 14 17:27:56 2024 daemon.notice netifd: Quectel (20268): Command failed: ubus call network.interface notify_proto { "action": 0, "link-up": false, "keep": false, "interface": "Quectel" } (Permission denied)