lycamobile/de: Can send SMS over 3G only, can't receive SMS

Since lots of the SMS/data/IP problems are dependent on a provider let's try bugs by provider/country:

With a lycamobile prepaid sim i can:

• call/answer without problems
• only send SMS in 3G mode
• not receive any SMS

SMS sending

So SMS send works with this setting:

mmcli -m 0 --set-allowed-modes="3g"
[wait...]
mmcli -m 0 | grep 'access tec'
           |          access tech: umts

Although SMS in other modes are markes as sent:

$ mmcli -m 0 --messaging-list-sms
    /org/freedesktop/ModemManager1/SMS/4 (sent)
    /org/freedesktop/ModemManager1/SMS/3 (sent)
    /org/freedesktop/ModemManager1/SMS/2 (sent)
    /org/freedesktop/ModemManager1/SMS/1 (sent)
    /org/freedesktop/ModemManager1/SMS/0 (sent)

SMS receive

I don't receive any SMS and the phone i send from indicates a send failure quickly so it somehow gets notified from the provider (the receiving phone is not a L5 so i can't provide details). I don't have a smsc configured.