Problem with different trunks and IP-Dect

Weird experience today…
Freepbx with few Gigaset cordless registered via N670IP dect base , they work fine.
Two PJSIP trunk , one with registration to service provider, the other without registration to a local Cisco router acting as gateway between PSTN line (FXO) and pbx.
All machines are on the same lan subnet.
Incoming calls from both trunks routed via inbound route to a Yealink ip phone make it ring, answer is ok.
Calls routed to any of cordless phones are OK if coming from provider trunk, else fail if coming from Cisco gateway.

When calling from SIP provider:
Called PJSIP/222/sip:[email protected]:5060 (222=cordless extno 192.168.1.100=Dect-Base address)
PJSIP/222-00000387 is ringing

When calling from Cisco GW, just:
Called PJSIP/222/sip:[email protected]:5060
and after few seconds, “the person…is unavailable” message with CHANUNAVAIL trace (sorry cannot have log at this moment).

Of course pjsip endpoints (cordless) are available.
Same issue if Cisco GW calls are answered correctly from Yealink ip phone and blind-transferred to cordless: no cordless ring and disconnection (attended transfer make dect ring and answer but call fails when transferred).

Any suggestion ?