Measure is too long to fit on one page, doesn't wrap

Musescore appears not to wrap measures over multiple lines if they contain too many notes.

I can of course split the huge single measure into multiple individual ones, but this messes with measure numbering (which I don't want to do for a classical piece – I would like to keep the measure numbers as written by the composer).

You can see in the screenshots that either notes of the long measure are missing or the measure numbers are incorrect.

Is there a way of telling Musescore to create a line break within a measure, without creating a new measure? Is there another workaround you can think of?

Thanks,
Geordie