#55 Error in QMI and MBMI with Quectel EP06-E

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'

Revision: EP06ELAR04A04M4G


 #55:  multiple PDN connections for a given APN not allowed 

Thanks for your query in Quectel forums.
EP06 supports ipv4 and ipv6. If the local operator’s network does not support ipv4, the module cannot be registered on ipv4, please confirm with the operator whether it supports ipv4 network, thank you.