I decided to change a soprano part to a tenor part, both voices using treble clef. The first stave of the new tenor part was labelled "Tenor" and from then on the beginning of the stave lines were marked quite simply with a "T".
After having to make some adjustments to the score, I now find that additional "T" s have begun to appear in odd places in the score. I can't get rid of them. Oddly, there has been no change to any of the beginnings of the tenor stave lines, which have all retained the original "T"
Grateful for any suggestions to delete these annoying glitches. Some photos are attached.