Import Musescore 1.3 into Musescore 3 - Voice won't adjust range

Hi,
I'm using Musescore 3.5 now. I imported an old score from 2014. I thought it was a Musescore 2 file, but I see that was not released until 2015.

I copied the file from an old backup folder to my new Scores folder and opened it.
I got a warning about the position of elements, which it offered to fix and I accepted.

As I recall the message referred to Musescore 1.3, so I guess it was from that version.

There were a few odd things, but overall things looked not too bad.

The one thing I'm trying to fix is the Voice range. It plays as a Soprano. I tried editing the Staff to change it to Tenor, but that does not change the way it plays and it now shows color-coded notes to show they are out of range for a Tenor.

Is there any way to fix this?

Score attached.

Thanks,
Ross