We would like to sort this out

Can you give us any further information?
What had you previously been doing in the app, how did you choose the song, was it the first song you choose when you opened the app, were you playing some songs then choose Stella, was the previous song using the Guitar diagrams font, have you seen this problem since then, can you replicate it, did you have Practice>transpose on ... etc?
What version of iReal Pro are you running?
Thanks.