Drumset slashes are displaying as normal noteheads

I’ve broken the drum kit slash instruments in my project. Even when I create a new drum kit (basic) any slash ‘instrument’, with or without stems, it displays as a standard note head. In a new project, these instruments display properly. What have I done? What can I do? Thanks.

I’ve cut the project down to just a few bars of the offending Drum Set part. Hoping somebody can take a look and advise. Thanks.
DrumSlashProblem.zip (628 KB)

Did you do any kind of kit export/import or similar? Once upon a time there was a bug that would cause slash components in drum kits to end up rendered as normal noteheads after importing a kit into the rpoject, but that was fixed some time ago. Are you running a reasonably up-to-date version of Dorico?

Hi Daniel - I am running I created this project by saving an older project and deleting all the music. I just went back to the older project, and while this project does have slashes (with stems) in the drum part, if I enter input mode, use the arrows to select the slash instrument, and type Y, I get a normal notehead not slashes.

If you want to email me your current project, I can try to fix it and send it back to you. My email address is d dot spreadbury at steinberg dot de.

For future reference: slashes only work if you have your layout options set for hands up / feet down voices. Single voice is no bueno.