EndCall Button not working with onhook

[GARP666]

Hi, all.
When i trying call from to externall call myAsteriskSCCP->myProvider->myAsteriskSCCP. When a call comes from an external provider, then when you press the hang up button (end the call), the button works, but the call on the phone is interrupted for a second and resumed. Is it possible to somehow solve this problem? This issue only occurs on external calls. I don't see this issue with internal calls.