I am using a Quectel EP06-E on OpenWrt 21.02-RC4 with modemmanager…
All was fine except from intermittent lost of connection.
But from 2 days now, I cannot get my wwan connect and get errors #55…
I am in France and trying to connect to Free Mobile Provider.
In QMI or MBMI modes, I always get error #55.
I can sometimes get IPV6 working, but never get IPV4V6 both working…
root@ULTRA-5G:~# sms_tool -d /dev/ttyUSB2 at 'ATI'
Quectel
EP06
Revision: EP06ELAR04A04M4G
http://howltestuffworks.blogspot.com/2012/02/pdn-connectivity-reject.html
#55: multiple PDN connections for a given APN not allowed