Whilst it used to be very simple ( prior to 1965) , the CE, Brexit and immigrants have made it much more complicated
ring the passport office as advised
but I wd renew your Italian one as simplest - having made SURE that they will let you back if you leave
My late lady mother had this ( India 1947) and it is an awful run around, but once sorted is OK. - and my father Belgian 1958, ( naturalised) - they didnt worry about all this when he was fighting for King George by the way - all comers welcome