Comment # 4 on bug 912584 from Christian Boltz

(In reply to Richard Weinberger from comment #3)
> BTW: After I got rid of all AppArmor stuff my WWAN works perfectly fine
> again.
> Maybe some AppArmor profile is too restrictive...

Please provide the AppArmor logs ;-)
- if you have auditd running, /var/log/audit/audit.log
- if you use syslog,   grep apparmor /var/log/messages
- if you only have journald running,   journalctl -b | grep apparmor
  for all messages since this boot (use -b1 for previous boot etc.)