I use 1 (default) identity only, it is without changes.
1) I replay to message addressed to me via "To:" field. New dialog for writing the message is opened, and my address is used in "From:" field. That's fine.
2) I replay to message addressed to me via "Cc:" field. New dialog for writing message is opened, but "From:" field is empty
(I see "Choose which identity to send this message from" transparent text there). Icon for sending message is unselectable.
I have to click to this field and select my address. The same bug I see for forwarding messages.

I think that "From:" field would contain default or preferred identity in all cases.

I use current git SOGo version.

Thanks,
Milos