This is a question about one note in the slow movement of the R-K Trombone Concerto.
Twenty six bars after the start of the slow movement (6/8), the last note in the bar is Eb

:line5: in the version from ISMLP but in my old version , the Harold Perry edition by Boosey and Hawkes, it is an F. Harmonically, I suspect that the Eb is correct, but can anyone please clarify this?
I have searched both TC and TTF but could not find anything.
Thanks and stay safe
Stewbones 43