message from user hooks R11 vs R12

Hello Team,
I'm struggling in getting fnd_messages from aso_quote_cuhk.UPdate_quote_POST user hook.
Hook is enabled Execute_flag= 'Y' (and for testing purposes is the only one enabled)

In R11 I had this lines raising messages from same hook
             x_return_status := Fnd_Api.G_RET_STS_ERROR;
             Fnd_Message.Set_Name('ASO', 'XXCVT_ASO_QOT_UPDATEPOST_ER01');            
             Fnd_Msg_Pub.ADD;
             x_msg_count := 1;
             x_msg_data := fnd_message.get;
   
In R11 I got message both from
Quoting sales Manager (form resp)
and
Sales OnLine Supr user (HTML resp)

I' don't see the message when  trying to get same output from R12 with same code lines