ATC keeps telling me to do this over and over again (I am above FL180 or at cruise altitude) but what do they want me to do? The PFE pilot just acknowledges... (I am on Auto2). Can't find any info, in user guide or otherwise. When I tried hitting '0', I was told Radio Service had been terminated (though I am still getting instructions re. altitude).
What did I miss? Not had this before. Thanks!