Issues with Fanvil i62

[SimoneDG]

Good morning,
I have a 3CX v20 update 7 PBX with two I62 intercoms and three x4u-v2 phones, and the other users use the web client or smartphone app.
When I make a call from the video intercom:
-If I answer from the Fanvil phones, I can open the call with the "*" code;
-If I answer from the 3CX smartphone app, I see the video, but when I press "*" to open the call, it doesn't open;
-If I answer from the web client, the keypad isn't enabled to type "*" either;

The Fanvil i62 firmware version is 2.12.51.
I've also tried other versions, but the problem persists.
Has anyone had the same or a similar problem?
Were you able to resolve it?

Thanks