[asterisk-users] Call didn't stop after losing one leg

[lm]

Hello there,

I'm using a Debian box with Asterisk 1.8.13.1 as a DID-PSTN gateway,
so I can receive calls in a DID number and redirect it to my mobile line.

It has been working flawlessly for a few months, but I have noticed
that some calls were not cut after losing one leg (the one with the
DID server), and kept the PSTN leg active until I restarted the
server (with the unexpected cost involved in the PSTN call).

The relevant extensions.conf line is:

exten => 34911234567,1,Dial(SIP/pstn/447123456789)

And both DID and PSTN sip accounts have canreinvite=yes, so they
can have direct media.

I haven't collected any debug log nor any other relevant information.

Does anybody know why something like this happens, or how can I
cut a call that unexpectedly losed a leg?

Thanks!
L.