TT550, I don't hear ALL messages any more

Dear TT users,
small probably stupid question,
Using TT550, Schubert SC1 & iPhone,
the connection is ok, on the moment I switch on, it gives me an OK, If there is a Radar Control, it tells me (which is great) but lately I do not get messages on where to got to (the standard" take next one to the left in 500 m" or something like that).
So,
I have to assume (as it does give the other messages, I must have switched the "Directional" messages OFF (definitely unintentionally) so WHERE I can switch that "ON" again ?

regards,
Leon