I'm using just mobile network for getting access to internet.
I have configured it to get an IPv6 address and it's successfully connected to IPv6-internet.
But after a while the router stops working for IPv6. Logs doesn't say anything special.
I log into my teltonika router and get this when trying ping6
root@Teltonika-RUTX11:~# ping6 ftp.sunet.se
PING ftp.sunet.se (2001:6b0:19::165): 56 data bytes
ping6: sendto: Permission denied
Rebooting the device restores IPv6-address for a while but it stops working after a bit again.